A Phase 3, Randomized, Observer-blind, Active-controlled Study to Evaluate the Safety and Efficacy of mRNA-1010 Candidate Seasonal Influenza Vaccine in Adults 50 Years and Older
Phase: PHASE3
Conditions: Seasonal Influenza
Sponsor: ModernaTX, Inc.

ModernaTX, Inc. 
Protocol mRNA-1010-P302 Amendment 1 
mRNA-1010 
Confidential 
Page 1 
CLINICAL STUDY PROTOCOL 
Protocol Title: 
A Phase 3, Randomized, Observer-blind, Active-controlled 
Study to Evaluate the Safety and Efficacy of mRNA-1010 
Candidate Seasonal Influenza Vaccine in Adults 50 Years and 
Older 
Protocol Number: 
mRNA-1010-P302 
Sponsor Name: 
ModernaTX, Inc. 
Legal Registered Address: 
200 Technology Square 
Cambridge, MA 02139 
Sponsor Contact and 
Medical Monitor: 
 
 
ModernaTX, Inc. 
Telephone: 
 
e-mail: 
Regulatory Agency 
Identifier Number(s): 
IND: 27460 
EudraCT: 2022-001638-12 
Date of Amendment 1: 
02 Feb 2023 
Date of Original Protocol: 
26 May 2022 
CONFIDENTIAL 
All financial and nonfinancial support for this study will be provided by ModernaTX, Inc. The 
concepts and information contained in this document or generated during the study are 
considered proprietary and may not be disclosed in whole or in part without the expressed 
written consent of ModernaTX, Inc. The study will be conducted according to the 
International Council for Harmonisation (ICH) of Technical Requirements for Registration of 
Pharmaceuticals for Human Use, E6(R2) Good Clinical Practice (GCP) Guidance. 
NCT #: NCT05566639
PPD
PPD
PPD

ModernaTX, Inc. 
Protocol mRNA-1010-P302 Amendment 1 
mRNA-1010 
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PROTOCOL APPROVAL – SPONSOR SIGNATORY 
Study Title: 
A Phase 3, Randomized, Observer-blind, Active-controlled Study to 
Evaluate the Safety and Efficacy of mRNA-1010 Candidate Seasonal 
Influenza Vaccine in Adults 50 Years and Older 
Protocol Number: 
mRNA-1010-P302 
Date of Amendment 1: 02 Feb 2023 
Date of Original 
Protocol: 
26 May 2022 
 
Protocol accepted and approved by: 
 
See eSignature and date signed on 
last page of the document. 
 
 
 
 
 
ModernaTX, Inc. 
200 Technology Square 
Cambridge, MA 02139 
Telephone: 
 
 
Date 
 
 
 
PPD
PPD

ModernaTX, Inc. 
Protocol mRNA-1010-P302 Amendment 1 
mRNA-1010 
Confidential 
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DECLARATION OF INVESTIGATOR 
I have read and understood all sections of the protocol entitled “A Phase 3, Randomized, 
Observer-blind, Active-controlled Study to Evaluate the Safety and Efficacy of mRNA-1010 
Candidate Seasonal Influenza Vaccine in Adults 50 Years and Older” dated 02 Feb 2023 and the 
most recent version of the Investigator’s Brochure. 
I agree to supervise all aspects of the protocol and to conduct the clinical investigation in 
accordance with the current Protocol, the International Council for Harmonisation (ICH) of 
Technical Requirements for Registration of Pharmaceuticals for Human Use, E6(R2) Good 
Clinical Practice (GCP) Guidance, and all applicable government regulations. I will not make 
changes to the protocol before consulting with ModernaTX, Inc. or implement protocol changes 
without IRB/IEC approval except to eliminate an immediate risk to participants.  
I agree to administer study treatment only to participants under my personal supervision or the 
supervision of a sub-investigator. I will not supply study treatment to any person not authorized 
to receive it. I also agree that persons debarred from conducting or working on clinical studies by 
any court or regulatory agency will not be allowed to conduct or work on studies for the sponsor 
or a partnership in which the sponsor is involved. I will immediately disclose it in writing to the 
sponsor if any person who is involved in the study is debarred, or if any proceeding for 
debarment is pending, or, to the best of my knowledge, threatened. 
I will not disclose confidential information contained in this document including participant 
information, to anyone other than the recipient study staff and members of the IRB/IEC. I agree 
to ensure that this information will not be used for any purpose other than the evaluation or 
conduct of the clinical investigation without the prior written consent from ModernaTX, Inc. I 
will not disclose information regarding this clinical investigation or publish results of the 
investigation without authorization from ModernaTX, Inc. 
The signature below provides the necessary assurance that this study will be conducted 
according to all stipulations of the protocol, including statements regarding confidentiality, and 
according to local legal and regulatory requirements, US federal regulations, and ICH E6(R2) 
GCP guidelines. 
Signature of Principal Investigator 
 
 
Date 
 
 
 
 
Printed Name of Principal Investigator 
 
 
 

ModernaTX, Inc. 
Protocol mRNA-1010-P302 Amendment 1 
mRNA-1010 
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PROTOCOL AMENDMENT SUMMARY OF CHANGES 
 
DOCUMENT HISTORY 
Document 
Date 
Amendment 1 
02 Feb 2023 
Original Protocol 
26 May 2022 
Global Amendment 1, 02 Feb 2023: Current Amendment 
This amendment is considered to be substantial, based on the criteria set forth in Article 10(a) of 
Directive 2001/20/EC of the European Parliament and the Council of the European Union. 
Main Rationale for the Amendment: 
The main purpose of this amendment is to prespecify immunogenicity analysis for HAIs and 
alter the timing of an Interim Analysis. The summary of changes table describes the changes 
made in Amendment 1, relative to the original protocol, including the sections modified and the 
corresponding rationales. Minor editorial or formatting changes, including removal of redundant 
text or text not appropriate for the synopsis, are not included in the summary table. Additional 
country-specific changes are provided in Section 11.6. 
Summary of Changes in Protocol Amendment 1: 
Section # and Name 
Description of Change 
Brief Rationale 
Title Page 
Sponsor contact updated. 
Administrative change. 
Title Page, Signature Page, 
Protocol Amendment Summary of 
Changes, Header 
Updated the protocol version 
and date, as applicable. 
To reflect the current version. 
Section 1.1, Protocol Synopsis, 
Section 5.1, Inclusion Criteria, 
Section 5.2, Exclusion Criteria, and 
Table 2 
Updated to clarify that culture-
confirmed protocol-defined ILI 
cases caused by any influenza A 
or B strains will be included in 
the endpoint regardless of 
antigenic match to strains 
selected for the seasonal 
vaccine. 
Added evaluation of humoral 
immunogenicity to secondary 
objectives. 
To remove redundant 
language of protocol-defined 
ILI cases caused by 
antigenically matched strains 
in the vaccines that are 
already summarized in other 
objectives/endpoints. 
To allow for earlier timing of 
sample testing, as it was 
initially part of an exploratory 
analysis that was planned for 
a later time. 
Section 1.2, Schedule of Events, 
Section 4.1, Study Design, and 
Section 8.9.2, Assessments for 
Respiratory Viral Infections 
Clarified that participants who 
experience protocol-defined ILI 
must have an NP swab collected 
for RT-PCR testing of influenza 
virus and other respiratory 
pathogens. In participants who 
Clarification based on study 
site feedback per IRB-
notified/approved 
clarification memo. 

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Protocol mRNA-1010-P302 Amendment 1 
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Section # and Name 
Description of Change 
Brief Rationale 
experience ILI symptoms but 
have not yet fulfilled protocol-
defined ILI, Investigators may 
use their discretion to perform 
NP swabs when influenza is 
suspected. 
Section 6.5.2, Concomitant 
Medications and Vaccines that 
May Lead to the Elimination of a 
Participant from Per-Protocol 
Analyses, and Section 9.4, 
Analysis Populations 
Further information is added to 
clarify concomitant medications 
and/or vaccines that may lead to 
a participant being excluded 
from the PP Set and analyses: 
− 
An authorized or 
licensed noninfluenza 
vaccine that is not 
adjuvanted administered 
within 14 days before or 
after the study 
intervention. 
− 
An authorized or 
licensed adjuvanted, 
noninfluenza vaccine 
administered within 28 
days after the study 
intervention. 
− 
Any nonstudy influenza 
vaccine administered 
during the study period. 
To describe details on usage 
of noninfluenza and influenza 
vaccines during the study that 
may result in exclusion from 
the PP Set. 
Section 8.10.2, Serious Adverse 
Events 
Revised definition of serious 
adverse events as follows: 
Persistent or significant 
disability or incapacity or 
substantial disruption of the 
ability to conduct normal life 
functions. 
To address health authority 
feedback. 
Section 8.15 Biomarkers 
Replaced the term, “additional” 
in front of the word 
“biomarkers” at the start of the 
paragraph.  
Deleted the word “exploratory” 
and replaced it with the words 
“future research.” 
Clarifications. 

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Protocol mRNA-1010-P302 Amendment 1 
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Section # and Name 
Description of Change 
Brief Rationale 
Added the words “from 
consented participants” at the 
end of the first paragraph. 
Shifted statement about 
“optional blood collections…” 
from the 1st paragraph to the 2nd 
paragraph and modified a 
portion of the statement starting 
with the following text, “…to 
research connections between 
vaccine responses and safet.” 
Added a statement at the end of 
the 2nd paragraph about NP 
swab collections. 
Section 9.2 Statistical Hypotheses 
Changed “2-sided” to “1-sided” 
and “5%” to “2.5%”. 
Changed the spending function 
from “O’Brien-Fleming” to 
“Pocock.” 
For noninferiority, the 1-sided 
P value is more applicable. 
The Pocock spending 
function provides a greater 
chance to achieve success at 
IA. 
Sections 9.2, Statistical 
Hypotheses, 9.3, Sample Size, 9.5, 
Statistical Analyses, 9.5.1.1, 
Analysis of Primary Efficacy 
Endpoint, 9.6, Planned Analyses, 
and Table 8 
The first IA was removed 
because of the expected lower 
power. 
The alpha spending function 
was changed to the Lan-DeMets 
Pocock approximation function 
to preserve the overall Type I 
error rate. 
Statistical considerations were 
updated because of the revised 
IA schedule and change in the 
alpha-spending function. 
The above success boundaries 
for hypothesis testing are 
changed to be in terms of 1-
sided P values.  
Per prediction, the timing of 
two IAs will be close. Hence, 
the Sponsor decided to 
combine them into one IA. 
The Pocock spending 
function provides a greater 
chance to achieve success at 
IA. 
For noninferiority, the 1-sided 
P value is more applicable.  
Section 9.3, Sample Size 
Allow the timing of IA based on 
a specified data cut-off date 
regardless of number of 
influenza cases accrued. 
Updated the power of the PP Set 
to 93%. 
To accommodate DSMB 
review even if the target 
number of cases for IA is not 
reached considering the 
declining influenza incidence. 

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Protocol mRNA-1010-P302 Amendment 1 
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Section # and Name 
Description of Change 
Brief Rationale 
Replaced “2 IAs” with “one IA” 
and deleted associated text 
about the percentages of the 
target total number of cases. 
Changed “2-sided” to “1-sided” 
and “5%” to “2.5%”. 
Changed the spending function 
from “O’Brien-Fleming” to 
“Pocock.” 
Section 9.4, Analysis Populations 
The mITT Set definition was 
revised. Randomized 
participants who discontinued 
from the study prior to 14 days 
after administration of study 
vaccines will be excluded. 
The PP Set definition was 
revised based on edits to the 
mITT Set. 
An Immunogenicity Subset and 
a PP Immunogenicity Subset 
was added. 
The revised definition will 
include more participants in 
the mITT Set. In addition, the 
influenza symptom reporting 
from 14 days post-
vaccination is not required. 
The additional subsets clarify 
which participants will be 
included in the 
immunogenicity analyses. 
Section 9.5.1.1, Analysis of 
Primary Efficacy Endpoint 
Added summary description of 
how missing data will be 
handled. 
Clarified that the randomization 
strata will be used as strata 
variables in the statistical model.  
To address health authority 
feedback. 
Section 9.5.3, Immunogenicity 
Analyses 
Added summary description of 
how immunogenicity will be 
analyzed. 
To describe the analysis for 
immunogenicity. 
Section 11.6 APPENDIX 6; 
Country-specific Requirements 
Added new Section displaying 
all prior country country-
specific amendments. 
To align with standard 
operating procedure of 
incorporating all prior 
country-specific amendments 
into a global amendment 
document.  
Abbreviations: DSMB = Data Safety Monitoring Board; IA = Interim analysis; ILI = Influenza-like illness; NP = 
Nasopharyngeal; PP = Per-protocol. 
 

ModernaTX, Inc. 
Protocol mRNA-1010-P302 Amendment 1 
mRNA-1010 
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1. 
PROTOCOL SUMMARY 
1.1. 
Protocol Synopsis 
Name of Sponsor/Company: ModernaTX, Inc. 
Name of Study Intervention: mRNA-1010 
Protocol Number: mRNA-1010-P302 Amendment 1 
Protocol Title: A Phase 3, Randomized, Observer-blind, Active-controlled Study to Evaluate 
the Safety and Efficacy of mRNA-1010 Candidate Seasonal Influenza Vaccine in Adults 
50 Years and Older 
Brief Title: A Phase 3 Study to Evaluate the Safety and Efficacy of mRNA-1010 Candidate 
Seasonal Influenza Vaccine in Adults 50 Years and Older 
Regulatory Agency Identifier Number (s): IND: 27460, EudraCT: 2022-001638-12 
Rationale: Seasonal influenza viruses are estimated by the World Health Organization 
(WHO) to cause 3 to 5 million cases of severe illness and up to 650,000 deaths each year 
resulting in a severe challenge to public health (WHO 2018). Influenza epidemics occur each 
year and follow a seasonal circulation pattern with increased cases during the winter months in 
the Northern Hemisphere (NH) and Southern Hemisphere (SH) (Riedel et al 2019). Based on 
the observed circulation patterns and antigenic changes, an expert panel recommends 
influenza virus strains to be used for vaccine manufacturing twice a year (once for the NH and 
once for the SH). Influenza A and influenza B viruses are the most relevant influenza viruses 
for human infection. Therefore, current vaccine recommendations include 1 influenza A H1N1 
strain, 1 influenza A H3N2 strain, and 2 influenza B strains (covering the B/Victoria and 
B/Yamagata lineages). 
Currently licensed seasonal influenza virus vaccines rarely exceed 60% overall effectiveness 
and are poorly effective during years when the circulating viruses do not match the strains 
selected for the vaccine antigens (CDC 2020a). Influenza vaccines based on messenger RNA 
(mRNA)-technology could provide several benefits compared to current vaccines, including 
the ability to respond to strain changes more quickly, avoidance of mutations that may be 
acquired during vaccine production in eggs or cell culture, stronger immune responses as well 
as improved protection in older adults (Rockman et al 2020). 
Objectives and Endpoints 
Primary Objectives 
Primary Endpoints 
• 
To evaluate the safety and reactogenicity 
of mRNA-1010 during the treatment 
period (28 days after study intervention) 
and follow-up period (period following the 
treatment period). 
• 
Solicited local and systemic ARs through 
7 days after study injection. 
• 
Unsolicited AEs through 28 days after study 
injection. 

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Protocol mRNA-1010-P302 Amendment 1 
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• 
MAAEs from Day 1 to Day 361 
(Month 12)/EoS. 
• 
AESIs from Day 1 to Day 361 
(Month 12)/EoS. 
• 
SAEs from Day 1 to Day 361 
(Month 12)/EoS. 
• 
AEs leading to discontinuation from Day 1 to 
Day 361 (Month 12)/EoS. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 as compared to an active 
comparator against influenza caused by 
any influenza A or B virus strains using 
protocol-defined ILI definition. 
• 
First episode of RT-PCR confirmed protocol-
defined ILI that begins at least 14 days post 
vaccination through Day 181 (Month 6)/end 
of influenza season caused by any seasonal 
influenza A or B virus strains regardless of 
antigenic match to strains selected for the 
seasonal vaccine. 
Secondary Objectives 
Secondary Endpoints 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 vaccine as compared to an 
active comparator against influenza caused 
by influenza A or B strains with similaritya 
to the vaccine strains using protocol-
defined ILI definition. 
• 
First episode of RT-PCR confirmed protocol-
defined ILI that begins at least 14 days post 
vaccination through Day 181 (Month 6)/end 
of influenza season caused by influenza A or 
B strains with similaritya to those selected for 
the seasonal vaccine. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 vaccine as compared to an 
active comparator against influenza caused 
by influenza A or B strains antigenically 
matched to the vaccine strainsb using 
protocol-defined ILI definition. 
• 
First episode of RT-PCR confirmed protocol-
defined ILI that begins at least 14 days after 
vaccination through Day 181 (Month 6)/end 
of influenza season caused by influenza A or 
B strains antigenically matched to the vaccine 
strainsb selected for the seasonal vaccine. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 vaccine as compared to an 
active comparator against influenza caused 
by influenza A or B strains (any strains or 
similar strains or antigenically matched 
strains) using CDC-defined ILI definition. 
• 
First episode of RT-PCR confirmed US 
CDC-defined ILI that begins at least 14 days 
after vaccination through Day 181 
(Month 6)/end of influenza season caused by  
− 
Any influenza A or B strains; 
− 
Influenza A or B strains with similarity to 
vaccine strains; 
− 
Influenza A or B strains that are 
antigenically matched to vaccine strains. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 vaccine as compared to an 
active comparator against culture-
confirmed influenza caused by any 
influenza A or B strains.  
• 
First episode of culture-confirmed protocol-
defined ILI that begins at least 14 days post 
vaccination through Day 181 (Month 6)/end 
of influenza season caused by any influenza A 
or B strains regardless of antigenic match 
to strains selected for the seasonal vaccine. 
• 
First episode of culture-confirmed CDC-
defined ILI that begins at least 14 days post 

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vaccination through Day 181 (Month 6)/end 
of influenza season caused by any influenza A 
or B strains regardless of antigenic match 
to strains selected for the seasonal vaccine. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 as compared to an active 
comparator to prevent hospitalizations 
associated with influenza illness. 
• 
Hospitalizations associated with RT-PCR 
confirmed protocol defined ILI that begins at 
least 14 days post vaccination through 
Day 181 (Month 6)/end of influenza season 
caused by any strain of influenza virus 
regardless of antigenic match to the strains 
selected for the seasonal vaccine. 
• 
To evaluate the humoral immunogenicity 
of mRNA-1010 relative to that of an active 
comparator against vaccine-matched 
influenza A and B strains at Day 29 in a 
subset of participants. 
• 
GMT at Day 29 as measured by HAI assay. 
• 
Proportion of participants reaching 
seroconversion at Day 29 as measured by HAI 
assay. 
• 
The proportion of participants with a titer 
≥ 1:40 at Day 29 as measured by HAI assay. 
• 
GMFR comparing Day 29 to Day 1 (Baseline) 
as measured by HAI assay. 
Abbreviations: AE = Adverse events; AESI = Adverse events of special interest ARs = Adverse reactions; 
CDC = Centers for Disease Control and Prevention; CHF = Congestive heart failure; COPD = Chronic 
obstructive pulmonary disease; EoS = End of Study; EQ-5D-5L = EuroQoL-5 Dimension 5-Levels; GMFR = 
Geometric mean fold rise; GMT = Geometric mean titer; HAI = Hemagglutination inhibition; ILI = Influenza-
like illness; MAAEs = Medically attended AEs; QoL = Quality of life; RT-PCR = Reverse transcriptase 
polymerase chain reaction; SAE = Serious adverse events; US = United States; WPAI:ILI = Work productivity 
and activity impairment questionnaire: Influenza-like illness. 
Note: Exploratory objectives may be performed. Refer to Section 3 for further details. 
a 
Similarity to strains selected for the seasonal vaccine based on antigenicity testing and/or genomic 
sequencing. 
b 
Antigenically matched to strains selected for the seasonal vaccine based on antigenicity testing. 
Overall Study Design: 
This study will be a Phase 3, randomized, observer-blinded, active-controlled trial to evaluate 
the safety and efficacy of mRNA-1010 in adults 50 years and older. 
Approximately 23,000 participants will be randomized in a 1:1 ratio to receive a single dose of 
mRNA-1010 at 
 µg total mRNA or a single dose of the active comparator. 
Brief summary: 
The purpose of this study is to measure relative vaccine efficacy (rVE) of mRNA-1010 as 
compared to an active comparator to prevent the occurrence of the first episode of reverse 
transcriptase-polymerase chain reaction (RT-PCR) confirmed protocol-defined influenza-like 
illness (ILI) caused by any influenza A or B virus strains. 
Study details include: 
• The study duration will be approximately 27 months (if 2 influenza seasons are 
required to perform efficacy analyses). 
CCI

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• There will be 6 safety telephone call visits at Days 8, 29 (except for those participants 
in the immune response biomarker subset which requires a clinic visit on Day 29), 91, 
181, 271, and 361 (Month 12)/end of study as specified in the Schedule of Events. 
• Approximately 1000 participants will be asked to provide blood samples at baseline 
and on Day 29 (28 days post vaccination) for assessment of immune responses to the 
study intervention, including anti-HA antibody responses to vaccine-matched strains 
(immune response biomarker subset). A clinic visit on Day 29 will be required for 
these participants. 
•  All participants will be asked to complete an electronic diary (eDiary) for solicited 
adverse reactions (ARs) from Day 1 to Day 7. 
Number of Participants: Approximately 23,000 participants will be enrolled. 
Note: Enrolled means participants’ agreement to participate in a clinical trial following 
completion of the informed consent process and screening. Potential participants who are 
screened for the purpose of determining eligibility for the study, but do not participate in the 
study, are not considered enrolled, unless otherwise specified by the protocol. A participant 
will be considered enrolled if the informed consent is not withdrawn prior to participating in 
any study activity after screening. 
Study Arms and Duration: 
• The study will comprise 2 study arms: investigational vaccine (mRNA-1010) group 
and active comparator (licensed quadrivalent inactivated seasonal influenzas vaccine) 
group. 
• The total study duration (including screening) for each participant is up to 13 months. 
Data Safety Monitoring Board: 
A Data Safety Monitoring Board (DSMB) will be used throughout the conduct of this study. 
This committee will be composed of independent members with relevant therapeutic and/or 
biostatistical expertise to allow for the ongoing review of safety data from this study 
population. Safety data will be reviewed according to intervals defined in the DSMB charter 
and will also occur as needed. 
 

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1.2. 
Schedule of Events 
Table 1: 
 
Schedule of Events 
Visit Number 
 
1 
2 
3 
4 
5 
6 
7 
USV 
Type of Visit/Contact 
C 
C 
SC 
C1/SC 
SC 
SC 
SC 
SC 
C 
Month Timepoint 
 
 
 
M1 
M3 
M6 
M9 
M12 
Up to 
M12 
Study Visit  
Screening2 
D1 
(Baseline) 
D8 
D29 
D91 
D181 
D271 
D361/EoS 
USV 
Window Allowance (Days) 
-28 
N/A 
±2 
-7 to +3 
±5 
±14 
±14 
±14 
N/A 
Informed consent form, demographics, vaccination and, 
medical history3  
X 
 
 
 
 
 
 
 
 
Inclusion/exclusion criteria 
X 
X 
 
 
 
 
 
 
 
Physical examination4 
X 
 
 
 
 
 
 
 
 
Vital signs5 
X 
X 
 
 
 
 
 
 
 
Pregnancy testing6 
X 
X 
 
 
 
 
 
 
 
Randomization 
 
X 
 
 
 
 
 
 
 
Blood collection for immune response biomarkers 
and/or transcriptomics (optional) subset7 
 
X 
 
X 
 
 
 
 
 
Blood collection for future research sample (optional)8 
 
X 
 
 
 
 
 
 
 
Study vaccination (including 30-minute post-dosing 
observation period)9 
 
X 
 
 
 
 
 
 
 
Collection of EFS10 
 
X 
 
 
 
 
 
 
 
NP swab for virus detection11 
 
 
 
 
 
 
 
 
X 
Follow-up safety call 
 
 
X 
X12 
X 
X 
X 
X 
 
eDiary activation for recording solicited ARs (7 days)13 
 
X 
 
 
 
 
 
 
 
Review of eDiary for solicited ARs14 
 
 
X 
 
 
 
 
 
 
Symptom Reporting eDiary activation15 
 
X 
 
 
 
 
 
 
 
Symptom Reporting eDiary for collection of symptoms 
of ILI16 
 
Twice weekly from Day 1 to Day 181 
Once weekly from 
Day 182 to Day 361 
 
Review of Symptom Reporting eDiary 
 
Review participant recorded ILI starting on Day 1 through Day 361 (Month 12)/EoS 
Telephone/electronic contacts to remind participants of 
ILI eDiary reporting17 
 
Once weekly from Day 1 to Day 181 
Every 2 weeks from 
Day 182 to Day 361 
 
eDiary collection of EQ-5D-5L18 
 
X 
 
 
X 
X 
X 
X 
X 
eDiary collection of WPAI:ILI 
 
 
eDiary prompts19 
Recording of unsolicited AEs 
 
X 
X 
X 
 
 
 
 
 

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Visit Number 
 
1 
2 
3 
4 
5 
6 
7 
USV 
Type of Visit/Contact 
C 
C 
SC 
C1/SC 
SC 
SC 
SC 
SC 
C 
Month Timepoint 
 
 
 
M1 
M3 
M6 
M9 
M12 
Up to 
M12 
Study Visit  
Screening2 
D1 
(Baseline) 
D8 
D29 
D91 
D181 
D271 
D361/EoS 
USV 
Window Allowance (Days) 
-28 
N/A 
±2 
-7 to +3 
±5 
±14 
±14 
±14 
N/A 
Recording of any SAEs, AESIs, and MAAEs, as well as 
AEs that led to discontinuation and relevant 
concomitant medications/procedures20 
 
X 
X 
X 
X 
X 
X 
X 
X 
Recording of concomitant medications and nonstudy 
vaccinations21 
 
X 
X 
X 
X 
X 
X 
X 
 
Recording of hospitalizations and outpatient treatment 
related to or for the treatment of the MAAE or SAE21 
 
X 
X 
X 
X 
X 
X 
X 
X 
Study completion 
 
 
 
 
 
 
 
X 
 
Abbreviations: AE = adverse event; AESI = adverse event of special interest; AR = adverse reaction; C = clinic; COVID-19 = coronavirus disease 2019; 
D = day; eCRF = electronic case report form; eDiary = electronic diary; EFS = Edmonton Frail Scale; EoS = end of study; EQ-5D-5L = EuroQol 5-dimension 
5-levels; EQ-VAS = EuroQol visual analogue scale; HRQoL = health-related quality of life; ILI = influenza like illness; IM = intramuscular; M = month; 
MAAE = medically attended adverse event; N/A = not applicable; NP = nasopharyngeal; SAE = serious adverse event; SARS-CoV-2 = severe acute 
respiratory syndrome coronavirus 2; SC = safety call (or contact by electronic means); USV = unscheduled visit; WPAI:ILI = Work Productivity and Activity 
Impairment Questionnaire: Influenza-like Illness. 
Note: In accordance with FDA Guidance on Conduct of Clinical Trials of Medical Products during the COVID-19 Public Health Emergency (FDA 2020), 
investigators may convert clinic visits to telemedicine visits with the approval of the Sponsor. 
1. 
Day 29 clinic visit is only required for participants in the immune response biomarker subset. 
2. 
The Screening visit and Day 1 may be performed on the same day or a different day. Additionally, the Screening visit may be performed over multiple 
visits if within the 28-day screening window. 
3. 
Verbal medical history is acceptable. 
4. 
A full physical examination, including height and weight, will be performed at the Screening visit; symptom-directed physical examinations may be 
performed at other clinic visits. Interim physical examinations will be performed at the discretion of the Investigator. Any clinically significant finding 
identified by a healthcare professional during clinic visits should be reported as an MAAE. 
5. 
Systolic and diastolic blood pressures, heart rate, respiratory rate, and body temperature. The preferred route of temperature assessment is oral. On the day 
of vaccination, vital signs will be collected once before vaccination and once 30 minutes after vaccination. Vital signs may be collected at other clinic 
visits in conjunction with a symptom-directed physical examination. 
6. 
A point-of-care urine pregnancy test will be performed at the Screening visit and before the vaccine dose on Day 1, if Day 1 is not on the same day as the 
Screening visit. At the discretion of the Investigator, a pregnancy test either via blood or point-of-care urine can be performed at any time. The 
participant’s follicle-stimulating hormone level may be measured at the Screening visit, as necessary, and at the discretion of the Investigator, to confirm 
postmenopausal status. 
7. 
In a subset of participants, samples will be collected for immunogenicity assessment and immune assessments. Of the people who participate in the subset, 
an additional blood sample collection for transcriptomics will be optional. Samples on Day 1 must be collected prior to receipt of vaccination. 
8. 
Sample collection for future research, including genomics, is optional. Samples on Day 1 must be collected prior to receipt of vaccination. 

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9. 
See Section 4.1 for dose levels and vaccination groups. All participants will be randomized to receive a single IM injection. 
10. Assessment of EFS will only be performed for participants aged 65 years and older.  
11. The NP swab specimen(s) for pathogens, including influenza virus and other respiratory pathogens (eg, SARS-CoV-2) will be collected any time from 
Day 1 to Day 361 (Month 12)/EoS if participants have protocol-defined ILI per the ILI Case Definitions in Section 8.10.5. or if deemed necessary per 
Investigator’s discretion when influenza is suspected. If participants experience ILI symptoms, they will be instructed to contact the clinic to determine if 
they need an NP swab collected for testing. NP swab collection should occur within 72 hours of symptom onset. NP swabs should be collected prior to any 
antiviral therapy, if possible. NP swabs may be collected as part of a home visit in lieu of a clinic visit. In the event that NP swabs during ILI cannot be 
collected, any available influenza testing results performed outside of the study should be captured in the eCRF. 
12. Only for those participants not in the immune response biomarker subset who otherwise would have a clinic visit this day. 
13. The eDiary entries will be recorded at approximately 30 minutes after injection while at the clinic with instruction provided by the clinic staff. Study 
participants will continue to record in the eDiary for solicited ARs each day after they leave the clinic, preferably in the evening and at the same time each 
day, on the day of injection and the subsequent 6 days following injection. See Section 8.9.4 for additional details. 
14. The site staff will review Symptom Reporting eDiaries daily and if illness symptoms are noted they should follow up with participants to determine if the 
symptoms warrant the participant providing an NP swab. Follow-up with the participant for symptoms review should be documented in eCRF. 
15. The Symptom Reporting eDiary will be activated for collection of ILI symptoms starting at Day 1 and lasting until Day 361 (Month 12)/EoS. 
16. Participants will be instructed to report via Symptom Reporting eDiary or telephone calls whether ILI symptoms have been experienced. If participants 
experience ILI symptoms, they will be instructed to contact the clinic as soon as possible to determine if an NP swab needs to be collected. NP swabs for 
testing should be collected within 72 hours of symptom onset. NP swabs should be collected prior to any antiviral therapy, if possible. NP swabs may be 
collected as part of a home visit in lieu of a clinic visit. 
17. Telephone/electronic contacts are to remind participants of ILI eDiary reporting, not to capture AEs. 
18. For participants reporting symptoms of ILI in the Symptom Reporting eDiary, the EQ-5D-5L responses will be collected using the eDiary on the day of the 
symptoms reporting (+1 day) and 5 days (+1 day) later. 
19. For participants reporting symptoms of ILI in the Symptom Reporting eDiary, the WPAI over the previous 7 days will be collected using the eDiary at 5 
days (+1 day) following the start of ILI symptoms reporting in the Symptom Reporting eDiary. 
20. Trained study personnel or designee will call all participants to collect information relating to any MAAEs, AEs leading to study discontinuation, SAEs, 
AESIs, and information on concomitant medications associated with those events. All concomitant medications relevant to or for the treatment of an SAE, 
AESI, or MAAE will be recorded from Day 1 through Day 361 (Month 12)/EoS. 
21. All concomitant medications and non-study vaccinations will be recorded through 28 days after study intervention (including receipt of any authorized or 
investigational COVID-19 vaccine). Additionally, certain concomitant medications will be recorded through Day 361/EoS (refer to Section 6.5.1). 
 

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TABLE OF CONTENTS 
CLINICAL STUDY PROTOCOL ..................................................................................................1 
PROTOCOL APPROVAL – SPONSOR SIGNATORY ................................................................2 
DECLARATION OF INVESTIGATOR .........................................................................................3 
PROTOCOL AMENDMENT SUMMARY OF CHANGES ..........................................................4 
1. 
PROTOCOL SUMMARY ............................................................................................8 
1.1. 
Protocol Synopsis .........................................................................................................8 
1.2. 
Schedule of Events .....................................................................................................12 
TABLE OF CONTENTS ...............................................................................................................15 
LIST OF TABLES .........................................................................................................................20 
LIST OF FIGURES .......................................................................................................................20 
LIST OF ABBREVIATIONS ........................................................................................................21 
2. 
INTRODUCTION ......................................................................................................24 
2.1. 
Study Rationale ...........................................................................................................24 
2.2. 
Background and Overview .........................................................................................24 
2.2.1. 
Nonclinical Studies .....................................................................................................25 
2.2.2. 
Clinical Studies ...........................................................................................................26 
2.3. 
Benefit/Risk Assessment ............................................................................................27 
2.3.1. 
Known Potential Benefits ...........................................................................................27 
2.3.2. 
Risks from Study Participation and Their Mitigation .................................................27 
2.3.3. 
Overall Benefit/Risk Conclusion ................................................................................28 
3. 
OBJECTIVES AND ENDPOINTS ............................................................................29 
4. 
STUDY DESIGN .......................................................................................................32 
4.1. 
General Design ...........................................................................................................32 
4.2. 
Scientific Rationale for Study Design ........................................................................34 
4.3. 
Justification for Dose, Control Product, and Choice of Study Population .................34 
4.4. 
End of Study Definition ..............................................................................................35 
5. 
STUDY POPULATION .............................................................................................36 
5.1. 
Inclusion Criteria ........................................................................................................36 
5.2. 
Exclusion Criteria .......................................................................................................36 
5.3. 
Lifestyle Restrictions ..................................................................................................38 
5.4. 
Screen Failures ............................................................................................................38 

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6. 
STUDY TREATMENT ..............................................................................................39 
6.1. 
Study Intervention(s) Administered ...........................................................................39 
6.2. 
Randomization and Blinding ......................................................................................39 
6.3. 
Preparation/Handling/Storage/Accountability ............................................................40 
6.3.1. 
Clinical Study Material Preparation ...........................................................................40 
6.3.2. 
Clinical Study Material Administration......................................................................40 
6.3.3. 
Clinical Study Material Packaging and Labeling .......................................................41 
6.3.4. 
Clinical Study Material Storage ..................................................................................41 
6.3.5. 
Clinical Study Material Accountability ......................................................................41 
6.3.6. 
Clinical Study Material Handling and Disposal .........................................................41 
6.3.7. 
Unblinding ..................................................................................................................41 
6.4. 
Study Intervention Compliance ..................................................................................42 
6.5. 
Concomitant Therapy .................................................................................................42 
6.5.1. 
Recording of Concomitant Medications and Concomitant Vaccinations ....................42 
6.5.2. 
Concomitant Medications and Vaccines that May Lead to the Elimination of 
a Participant from Per-Protocol Analyses ....................................................................43 
6.6. 
Continuous Access to Study Intervention After the End of the Study .......................43 
7. 
DELAY OR DISCONTINUATION OF STUDY INTERVENTION AND 
PARTICIPANT DISCONTINUATION/WITHDRAWAL .......................................44 
7.1. 
Participant Discontinuation/Withdrawal from the Study ...........................................44 
7.2. 
Lost to Follow up ........................................................................................................45 
8. 
STUDY ASSESSMENTS AND PROCEDURES ......................................................46 
8.1. 
Screening ....................................................................................................................46 
8.2. 
Confirm Inclusion and Exclusion Criteria ..................................................................46 
8.3. 
Demographic and Baseline Data ................................................................................46 
8.4. 
Medical History ..........................................................................................................46 
8.5. 
Randomization ............................................................................................................46 
8.6. 
Physical Examination and Vital Signs ........................................................................46 
8.7. 
Study Vaccine Administration ....................................................................................47 
8.8. 
Efficacy Assessments .................................................................................................47 
8.9. 
Safety Assessments .....................................................................................................47 
8.9.1. 
Pregnancy Screen and Testing ....................................................................................48 
8.9.2. 
Assessments for Respiratory Viral Infections ............................................................48 

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8.9.3. 
Safety Telephone Calls ...............................................................................................49 
8.9.4. 
Use of Electronic Diaries ............................................................................................49 
8.9.5. 
Recording and Follow-up of Pregnancy .....................................................................50 
8.9.6. 
Recording and Follow-up of an AE and/or SAE ........................................................50 
8.9.7. 
Reporting Adverse Events ..........................................................................................51 
8.9.8. 
Reporting Serious Adverse Events .............................................................................51 
8.9.9. 
Time Period and Frequency for Collecting AE and SAE Information .......................52 
8.9.10. 
Method of Detecting AEs and SAEs ..........................................................................52 
8.9.11. 
Regulatory Reporting Requirements for SAEs ...........................................................52 
8.9.12. 
Blood Sampling Volumes ...........................................................................................53 
8.9.13. 
Ancillary Supplies for Participant Use .......................................................................53 
8.10. 
Safety Definitions .......................................................................................................53 
8.10.1. 
Adverse Event .............................................................................................................53 
8.10.2. 
Serious Adverse Events ..............................................................................................54 
8.10.3. 
Solicited Adverse Reactions .......................................................................................55 
8.10.4. 
Medically Attended Adverse Events ..........................................................................57 
8.10.5. 
Influenza-like Illness Case Definitions .......................................................................57 
8.10.6. 
Adverse Events of Special Interest .............................................................................57 
8.10.7. 
Assessment of Intensity/Severity ................................................................................59 
8.10.8. 
Assessment of Causality .............................................................................................59 
8.11. 
Safety Oversight .........................................................................................................60 
8.11.1. 
Data and Safety Monitoring Board .............................................................................60 
8.11.2. 
Independent Cardiac Event Adjudication Committee ................................................60 
8.12. 
Treatment of Overdose ...............................................................................................60 
8.13. 
Pharmacokinetics ........................................................................................................60 
8.14. 
Pharmacodynamics .....................................................................................................60 
8.15. 
Biomarkers ..................................................................................................................61 
8.16. 
Patient-Reported Outcomes and Medical Resource Utilization .................................61 
8.16.1. 
Patient-reported Outcome Measures ...........................................................................61 
8.16.2. 
Medical Resource Utilization .....................................................................................62 
9. 
STATISTICAL CONSIDERATIONS .......................................................................63 
9.1. 
Blinding and Responsibility for Analyses ..................................................................63 
9.2. 
Statistical Hypotheses .................................................................................................63 

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9.3. 
Sample Size ................................................................................................................64 
9.4. 
Analyses Populations ..................................................................................................65 
9.5. 
Statistical Analyses .....................................................................................................66 
9.5.1. 
Efficacy Analyses .......................................................................................................67 
9.5.2. 
Safety Analyses ..........................................................................................................68 
9.5.3. 
Immunogenicity Analyses ..........................................................................................69 
9.5.4. 
Exploratory Analyses ..................................................................................................70 
9.5.5. 
Subgroup Analyses .....................................................................................................70 
9.6. 
Planned Analyses ........................................................................................................70 
9.6.1. 
Interim Analyses .........................................................................................................70 
9.6.2. 
Multiplicity .................................................................................................................71 
10. 
REFERENCES ...........................................................................................................74 
11. 
SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS ..................................................................................................76 
11.1. 
APPENDIX 1: Study Governance Considerations .....................................................77 
11.1.1. 
Regulatory and Ethical Considerations ......................................................................77 
11.1.2. 
Study Monitoring ........................................................................................................77 
11.1.3. 
Audits and Inspections ................................................................................................78 
11.1.4. 
Financial Disclosure ...................................................................................................79 
11.1.5. 
Recruitment Strategy ..................................................................................................79 
11.1.6. 
Informed Consent Process ..........................................................................................79 
11.1.7. 
Protocol Amendments ................................................................................................80 
11.1.8. 
Protocol Deviations ....................................................................................................81 
11.1.9. 
Data Protection ...........................................................................................................81 
11.1.10. 
Sample Retention and Future Biomedical Research ..................................................82 
11.1.11. 
Data and Safety Monitoring Board .............................................................................82 
11.1.12. 
Dissemination of Clinical Study Data ........................................................................82 
11.1.13. 
Data Quality Assurance and Quality Control .............................................................82 
11.1.14. 
Data Collection and Management ..............................................................................83 
11.1.15. 
Source Documents ......................................................................................................84 
11.1.16. 
Retention of Records ..................................................................................................84 
11.1.17. 
Study and Site Closure................................................................................................84 
11.1.18. 
Publication Policy .......................................................................................................85 

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11.2. 
APPENDIX 2: Contraceptive Guidance .....................................................................86 
11.3. 
APPENDIX 3: Estimands and Estimand Specifications ............................................88 
11.4. 
APPENDIX 4: Adverse Events of Special Interest Terms .........................................89 
11.5. 
APPENDIX 5: CDC Working Case Definitions of Pericarditis, Myocarditis, 
and Myopericarditis Occurring After Receipt of COVID-19 mRNA 
Vaccines ......................................................................................................................90 
11.6. 
APPENDIX 6: Country-specific Requirements .........................................................92 
11.6.1. 
Protocol Amendment DNK-1 (Danish Country-specific Requirements), 26 
Oct 2022 ......................................................................................................................92 
11.6.2. 
Protocol Amendment GBR-1 (United Kingdom Country-specific 
Requirements), 22 Sep 2022 .......................................................................................92 
 
 
 

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LIST OF TABLES 
Table 1: 
 Schedule of Events ....................................................................................................12 
Table 2: 
Study Objectives and Endpoints .................................................................................29 
Table 3: 
 Vaccination Groups and Dose Levels ........................................................................32 
Table 4: 
Study Interventions .....................................................................................................39 
Table 5:  
Solicited Adverse Reactions and Grades ....................................................................55 
Table 6: 
Populations for Analyses ............................................................................................65 
Table 7: 
Analysis Strategy for Safety Parameters ....................................................................69 
Table 8: 
Interim Boundaries Using Lan-DeMets Pocock Spending Function, 
Calculation Based on the PP Set for the Endpoint Supporting the Primary 
Objective .....................................................................................................................71 
Table 9: 
Intercurrent Event Types ............................................................................................88 
Table 10: Primary Objective and Estimands with Rationale for Strategies to Address 
Intercurrent Events for Per-Protocol Analysis ............................................................88 
Table 11: Adverse Events of Special Interest .............................................................................89 
Table 12: Case Definitions of Probable and Confirmed Myocarditis, Pericarditis, and 
Myopericarditis ...........................................................................................................90 
 
LIST OF FIGURES 
Figure 1: 
Testing Sequence of the Primary and Secondary Endpoints ......................................72 
 

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LIST OF ABBREVIATIONS 
The following abbreviations and terms are used in this study protocol.  
Abbreviation or Specialist Term 
Definition 
ADR 
Adverse drug reaction 
AE 
Adverse event 
AESI 
Adverse event of special interest 
Ars 
Adverse reactions 
CDC 
Center for Disease Control and Prevention 
CEAC 
Cardiac Event Adjudication Committee 
CFR 
Code of Federal Regulations 
CHF 
Congestive heart failure 
CI 
Confidence Interval 
CONSORT 
Consolidated Standards of Reporting Trials 
COPD 
Chronic obstructive pulmonary disease 
COVID-19 
Coronavirus disease 2019 
CRO 
Clinical Research Organization 
DSMB 
Data Safety Monitoring Board 
eCRF 
Electronic case report form 
EFS 
Edmonton Frail Scale 
EoS 
End of Study 
EQ-5D-5L 
EuroQoL-5 Dimension 5-Levels 
EQ-VAS 
EuroQol visual analogue scale 
FAS 
Full Analysis Set 
GCP 
Good Clinical Practice 
GLSM 
Geometric least square mean 
GMP 
Good Manufacturing Practice 
GMT 
Geometric mean Titers 
HA 
Hemagglutinins 
HAI 
Hemagglutination inhibition 

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Abbreviation or Specialist Term 
Definition 
HCP 
Healthcare practitioner 
HIV 
Human immunodeficiency virus 
HR 
Hazard ratio 
IA 
Interim Analysis 
IB 
Investigator’s Brochure 
ICF 
Informed consent form 
ICH 
International Council on Harmonisation 
IEC 
Independent Ethics Committee 
IgG 
Immunoglobulin G 
ILI 
Influenza-like illness 
IM 
Intramuscular(ly) 
IRB 
Institutional Review Board 
IRT 
Interactive Response Technology  
LLOQ 
Lower limit of quantification 
LNP 
Lipid nanoparticles 
LTFU 
Lost to Follow-up 
MAAEs 
Medically attended adverse events 
MedDRA 
Medical Dictionary for Regulatory Activities 
mITT 
Modified intent-to-treat 
mRNA 
Messenger ribonucleic acid 
NH 
Northern Hemisphere 
NI 
Noninferiority 
NIM 
Noninferiority margin 
NP 
Nasopharyngeal 
PI 
Principal Investigator 
POCBP 
Participants of childbearing potential 
PP  
Per-protocol 
QoL 
Quality of life 

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Abbreviation or Specialist Term 
Definition 
RT-PCR 
Reverse transcriptase polymerase chain reaction 
rVE 
Relative vaccine efficacy 
SAE 
Serious adverse event 
SAP 
Statistical analysis plan 
SARS-CoV-2 
Severe acute respiratory syndrome coronavirus-2 
SD 
Standard deviation 
SH 
Southern Hemisphere 
SoE 
Schedule of Events 
TEAE 
Treatment-emergent adverse event 
ULOQ 
Upper limit of quantification 
US 
United States 
vs. 
versus 
WHO 
World Health Organization 
WPAI:ILI 
Work productivity and activity impairment questionnaire: 
influenza-like illness 

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2. 
INTRODUCTION 
2.1. 
Study Rationale 
Seasonal influenza viruses are estimated by the World Health Organization (WHO) to cause 3 to 
5 million cases of severe illness and up to 650,000 deaths each year resulting in a severe 
challenge to public health (WHO 2018). Influenza epidemics occur each year and follow a 
seasonal circulation pattern with increased cases during the winter months in the Northern 
Hemisphere (NH) and Southern Hemisphere (SH) (Riedel et al 2019). Since influenza viruses 
continuously change through a process termed antigenic drift, the circulating viruses are actively 
monitored by a worldwide network coordinated by the WHO (Monto 2018). Based on the 
observed circulation patterns and antigenic changes, an expert panel recommends influenza virus 
strains to be used for vaccine manufacturing twice a year (once for the NH and once for the SH). 
Influenza A and influenza B viruses are the most relevant influenza viruses for human infection. 
Therefore, current vaccine recommendations include 1 influenza A H1N1 strain, 1 influenza A 
H3N2 strain, and 2 influenza B strains (covering the B/Victoria and B/Yamagata lineages). 
Currently licensed seasonal influenza virus vaccines rarely exceed 60% overall effectiveness and 
are poorly effective during years when the circulating viruses do not match the strains selected 
for the vaccine antigens (CDC 2020a). Influenza vaccines based on messenger RNA 
(mRNA)-technology could provide several benefits compared to current vaccines, including the 
ability to respond to strain changes more quickly, avoidance of mutations that may be acquired 
during vaccine production in eggs or cell culture, stronger immune responses as well as 
improved protection in older adults (Rockman et al 2020). 
2.2. 
Background and Overview  
The Sponsor has developed a proprietary vaccine platform based on an mRNA delivery system. 
The platform is based on the principle and observations that cells in vivo can take up mRNA, 
translate it, and then express protein viral antigen(s) on the cell surface. The delivered mRNA 
does not enter the cellular nucleus or interact with the genome, is nonreplicating, and is 
expressed transiently. 
The Sponsor is using its mRNA-based platform to develop a lipid nanoparticle (LNP) 
encapsulated mRNA-based seasonal vaccine against disease caused by influenza virus types A 
and B. The proposed development candidate, mRNA-1010, will be a quadrivalent vaccine 
containing mRNAs encoding for the hemagglutinins (HAs) of the 4 strains recommended by 
WHO for cell- or recombinant-based vaccines. Equal amounts of mRNAs will be used for 
encoding the HA components for each of the 4 different strains. The mRNA-1010 development 
candidate is administered as a single dose and aims to elicit protection from all seasonal 
influenza viruses covered by the vaccine. 
The Sponsor has enrolled 880 participants in a Phase 1/2 trial with mRNA-1010 in the US and 
plans to enroll 6000 participants in a Phase 3 immunogenicity trial in the SH in Q2/Q3 2022. The 
Sponsor is conducting this Phase 3 trial with mRNA-1010 to establish safety and efficacy data to 
support the licensure for this vaccine. 
Details on the mechanism of action and a summary of nonclinical studies of mRNA-1010 can be 
found in Section 2.2.1. 

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This study will be conducted in compliance with the protocol, Good Clinical Practice (GCP), and 
all applicable regulatory requirements. 
2.2.1. 
Nonclinical Studies 
Using individually formulated HA encoding mRNAs (preclinical material), 2 mouse 
immunogenicity studies were performed. The HA sequences used for preclinical formulation 
were from wild type HAs. 
Both studies used a prime/boost regimen with a 3-week interval. Immunized mice were bled on 
Day 21 (3 weeks after the prime dose) and Day 36 (2 weeks after the boost dose), and 
immunoglobulin G (IgG) antibody titers were determined with an enzyme-linked immunosorbent 
assay using recombinant HA proteins. 
The first study compared mice immunized with individual mRNAs or a combination of all 4 HA 
mRNAs at 2 different doses (2 µg or 0.4 µg of each mRNA), based on the following strains 
recommended for the 2020 to 2021 NH influenza season: 
• A/Hawaii/70/2019(H1N1)pdm09 
• A/Hong Kong/45/2019(H3N2) 
• B/Washington/02/2019 (B/Victoria lineage) 
• B/Phuket/3073/2013 (B/Yamagata lineage) 
High IgG antibody titers were observed against all HAs following immunization with both 
individual mRNA constructs and mRNA combinations after a single dose. A dose response and 
booster effect were observed for most mRNA constructs (individual and combinations). 
The second mouse immunogenicity study aimed to confirm that the 2021 SH composition is 
similarly immunogenic with the 2020 to 2021 NH composition. The compositions differed only 
for the H1N1 strain; the SH composition included A/Wisconsin/588/2019(H1N1)pdm09 instead 
of the A/Hawaii/70/2019(H1N1)pdm09 strain. 
No difference in immunogenicity (HA IgG antibody titers) based on the strain/mRNA construct 
used for immunization (A/Hawaii/70/2019 in the NH composition versus A/Wisconsin/588/2019 
in the SH composition) was observed, suggesting that the mRNA platform will support annual 
strain updates. 
Additional studies to assess protection of mice from challenge with mouse adapted H1N1 and 
H3N2 viruses after a single immunization and a study to assess immunogenicity and protection 
from H1N1 challenge after 2 immunizations in ferrets have been completed. Using non-good 
manufacturing practices (GMP) co-formulated material, mice and ferrets were immunized with 
mRNA-1010 of the SH 2021 composition (mRNA-1010-SH21) followed by a viral challenge. 
Control animals were immunized with phosphate buffered saline or a commercially available 
MF59-adjuvanted influenza vaccine (FLUAD®, 2020/21 NH composition). 
Ferrets were administered the vaccine via intramuscular (IM) injection on a prime/boost schedule 
with a 3-week interval; antibody responses were measured at Day 21 and Day 42 followed by 
H1N1 challenge on Day 42. Mice received a single dose of vaccine via IM injection, antibody 
responses were measured at Day 21, and the animals were challenged that day with either an 
H1N1 or H3N2 virus. 

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In both animal models, serological analyses demonstrated that hemagglutination inhibition (HAI) 
antibody titers were detectable against the 4 viral strains after the first immunization with 
mRNA-1010 and in the case of ferrets, titers were further boosted by the second immunization. 
In addition, the HAI antibody titers induced by mRNA-1010 were as robust as the titers induced 
by the adjuvanted influenza vaccine (FLUAD). 
Upon live virus challenge, ferrets that were vaccinated with mRNA-1010 had lower detectable 
viral loads compared to the placebo group across different tissues. Compared to FLUAD, 
mRNA-1010 performed equally well and reduced viral loads to lower levels in the nose, throat, 
and nasal turbinates. No virus was detected in the lung, 4 days after challenge. 
Upon H3N2 live virus challenge, mice that were vaccinated with mRNA-1010 lost less weight 
and showed fewer clinical symptoms as compared to animals that received FLUAD or animals in 
the control group. Upon (H1N1)pdm09-like virus challenge, animals that received mRNA-1010 
or FLUAD were fully protected against morbidity and showed no scorable clinical symptoms. 
In conclusion, vaccination with mRNA-1010 induces strong antibody responses in mice and 
ferrets and confers protective efficacy against live virus challenge. 
A detailed review of the nonclinical observation with mRNA-1010 vaccine is provided in the 
Investigator’s Brochure (IB). 
2.2.2. 
Clinical Studies 
The Sponsor’s Phase 1/2 mRNA-1010-P101 trial (NCT04956575) is currently ongoing to 
provide initial first-in-human safety and immunogenicity data on 3 dose levels of mRNA-1010 
encoding strains (
 µg, 
 µg, or 
 µg total mRNA) recommended by the WHO for the 
2021 SH. An amendment to mRNA-1010-P101 includes a Phase 2 NH portion to the study to 
increase the size of the safety database for the 
 µg and 
 µg dose levels and to test an 
additional 
 µg dose level of mRNA-1010 as well as a licensed seasonal influenza vaccine as an 
active comparator. A Phase 2 extension portion to this trial is ongoing to study additional dose 
levels of mRNA-1010 
 µg and 
 µg) as well as 
 µg of mRNA-1010 and an active 
comparator. 
No significant safety concerns have been observed in the ongoing Phase 1/2 mRNA-1010-P101 
study upon review of safety data up to Day 29 by the Data Safety Monitoring Board (DSMB). In 
the trial, 45 participants in each group received 
 µg, 
 µg, or 
 µg doses of mRNA-1010. 
The 
-µg dose of mRNA-1010 showed a preferable reactogenicity profile. The local and 
systemic adverse reactions (ARs) were mostly mild to moderate in severity. There were no 
Grade 4 ARs or serious adverse events (SAEs) assessed by the Investigator as related to the 
study intervention. There was a death due to stage 4 kidney cancer that was unrelated to the 
study intervention and occurred after the Day 29 visit. Vaccination with mRNA-1010 elicited 
HAI antibodies in both younger and older adults against all strains at all dose levels. HAI titers 
elicited at the 
 µg dose level were comparable with the titers elicited at higher dose levels. 
The interim analysis (IA) from the Phase 2 NH part of mRNA-1010-P101 included data through 
Day 29 from 498 adults who received the study intervention. The number of participants in the 
4 groups were 151 (
 µg mRNA-1010), 147 (
 µg mRNA-1010), 147, (
 µg mRNA-1010), 
and 53 (Afluria®). No significant safety concerns were identified. The frequency and severity of 
the reports of solicited ARs in the mRNA-1010 groups increased in a dose-dependent manner 
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI
CCI

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particularly in the older age groups but were acceptable across all dose levels. The solicited ARs 
were higher in the mRNA-1010 groups than in the Afluria group. Local and systemic solicited 
ARs were mostly mild to moderate in severity without any Grade 4 ARs, adverse events of 
special interest (AESIs), or SAEs assessed to be related to the study intervention. There were no 
study discontinuations due to AEs, and no AEs that led to a study pause. There was 1 death due 
to cardiac arrest in a 67-year-old male participant with a relevant medical history of diabetes 
mellitus, hypertension, and obesity. The event occurred 15 days post study vaccination and was 
assessed by the Investigator to be unrelated to the study intervention. mRNA-1010 elicited high 
levels of HAI antibodies on Day 29 across all dose levels, substantially exceeding the 1:40 
threshold associated with a 50% reduction in risk of infection. Antibody responses induced by 
mRNA-1010 against the influenza A strains H1N1 and H3N2 were higher compared to Afluria 
and similar for the influenza B strains. 
A description of the immunogenicity and safety of mRNA-1010 is provided in the IB. 
2.3. 
Benefit/Risk Assessment 
2.3.1. 
Known Potential Benefits 
The mRNA-1010 vaccine may be effective against seasonal influenza strains as defined by the 
WHO. Considering the safety and immunogenicity data for mRNA-1010 to date, the Sponsor 
considers the potential benefits of participation to exceed the risks. 
Participants will obtain medical advice about their general health status through the medical 
evaluations/assessments associated with this study (ie, physical examination, vital signs 
measurement, and nasopharyngeal [NP] swabs testing). 
Participants will be contributing to the process of developing a new potentially prophylactic 
measure in an area of unmet medical need. 
2.3.2. 
Risks from Study Participation and Their Mitigation 
As with all injectable vaccines, immediate systemic allergic reactions to vaccination, ranging 
from mild allergic reactions (eg, urticaria) to systemic allergic reactions (eg, anaphylaxis) can 
occur. These reactions are very rare and are estimated to occur once per 450,000 vaccinations for 
vaccines that do not contain allergens such as gelatin or egg protein (Zent et al 2002). 
Since the authorization of the mRNA-1273 vaccine for coronavirus disease 2019 (COVID-19), 
the US Centers for Disease Control and Prevention (CDC) estimate of the rate of anaphylaxis 
based on reporting in the Vaccine Adverse Event Reporting System is approximately 2.5 
cases/million doses administered (Shimabukuro et al 2021). As a precautionary measure, all 
participants in this study will remain under observation at the clinic for at least 30 minutes after 
vaccination. 
Vasovagal syncope (fainting) can occur before or after any vaccination and is usually triggered 
by the pain or anxiety caused by the injection and is not related to the substance injected. 
Therefore, it is important that standard precautions and procedures be followed to avoid injury 
from fainting. 
IM injection with other mRNA vaccines manufactured by the Sponsor containing the proprietary 
SM-102 (heptadecan 9-yl 8-((2 hydroxyethyl)(6 oxo 6-(undecyloxy)hexyl)amino) octanoate) 

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lipid formulation have commonly resulted in transient and self-limiting local inflammatory 
reactions. These typically included pain, erythema (redness), or swelling (hardness) at the 
injection site, which were mostly mild to moderate in severity and usually occurred within 24 
hours of injection. 
Laboratory abnormalities (including increases in liver function tests and serum lipase levels) 
following injection have been observed in early phase clinical studies with similar mRNA-based 
vaccines. These abnormalities were without clinical symptoms or signs and returned toward 
baseline (Day 1) values over time. The clinical significance of these observations is unknown. 
IA safety results from the Phase 1/2 portion of mRNA-1010-P101 (data extraction date 
07 Oct 2021) demonstrated sporadic abnormalities for chemistry and hematology tests in all 
groups at 7 days post vaccination, but no trends or safety concerns were identified. There were 
no Grade 4 laboratory test abnormalities recorded in the study up to Day 29. 
The most commonly reported local solicited ARs after interim safety analysis in the mRNA-
1010-P101 trial were pain at injection site, axillary swelling, or tenderness. Injection site 
erythema or swelling was less frequently reported. The most common solicited systemic 
reactions were headache, fatigue, myalgia, and chills. Fever, nausea and arthralgia were reported 
less frequently. 
There have been very rare reports of myocarditis and pericarditis occurring after vaccination 
with COVID-19 mRNA vaccines. The majority of the cases have been reported in young males 
shortly after the second dose of the vaccine. These are typically mild cases and individuals tend 
to recover within a short time following standard treatment and rest. Investigators and study 
participants should be alert to the signs and symptoms of myocarditis and pericarditis (Gargano 
et al, 2021). 
Enhanced influenza vaccines (eg, adjuvanted, high dose, or recombinant vaccines) are 
preferentially recommended and available to the elderly (~65 years of age and older) in some 
countries. These vaccines are more efficacious in preventing influenza illness compared to 
standard dose vaccines (eg, the comparator Fluarix®). Moreover, the efficacy of mRNA-1010 is 
unknown and will be evaluated in this study. Therefore, elderly participants should be made 
aware of any available alternative option to receive an enhanced influenza vaccine during the 
consenting process. Nonstudy influenza vaccines are not permitted in the study. 
2.3.3. 
Overall Benefit/Risk Conclusion 
Considering the safety and immunogenicity data for mRNA-1010 to date, the Sponsor considers 
the potential benefits of participation to exceed the risks. 

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3. 
OBJECTIVES AND ENDPOINTS 
The objectives which will be evaluated in this study and endpoints associated with each objective 
are provided in Table 2. 
Table 2: 
Study Objectives and Endpoints
Primary Objectives 
Primary Endpoints 
• 
To evaluate the safety and reactogenicity of 
mRNA-1010 during the treatment period 
(28 days after study intervention) and 
follow-up period (period following the 
treatment period). 
• 
Solicited local and systemic ARs through 
7 days after study injection. 
• 
Unsolicited AEs through 28 days after study 
injection. 
• 
MAAEs from Day 1 to Day 361 
(Month 12)/EoS. 
• 
AESIs from Day 1to Day 361 (Month 12)/EoS. 
• 
SAEs from Day 1to Day 361 (Month 12)/EoS. 
• 
AEs leading to discontinuation from Day 1 to 
Day 361 (Month 12)/EoS. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 as compared to an active 
comparator against influenza caused by any 
influenza A or B virus strains using 
protocol-defined ILI definition. 
• 
First episode of RT-PCR confirmed 
protocol-defined ILI that begins at least 14 days 
post vaccination through Day 181 
(Month 6)/end of influenza season caused by 
any seasonal influenza A or B virus strains 
regardless of antigenic match to strains selected 
for the seasonal vaccine. 
Secondary Objectives 
Secondary Endpoints 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 vaccine as compared to an 
active comparator against influenza caused 
by influenza A or B strains with similaritya 
to the vaccine strains, using protocol-
defined ILI definition. 
• 
First episode of RT-PCR-confirmed protocol 
defined ILI that begins at least 14 days post 
vaccination through Day 181 (Month 6)/end of 
influenza season caused by influenza A or B 
strains with similaritya to those selected for the 
seasonal vaccine. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 vaccine as compared to an 
active comparator against influenza caused 
by influenza A or B strains antigenically 
matched to the vaccine strainsb using 
protocol-defined ILI definition. 
• 
First episode of RT-PCR confirmed 
protocol-defined ILI that begins at least 14 days 
after vaccination through Day 181 
(Month 6)/end of influenza season caused by 
influenza A or B strains antigenically matched 
to the vaccine strainsb selected for the seasonal 
vaccine. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 vaccine as compared to an 
active comparator against influenza caused 
by influenza A or B strains (any strains or 
similar strains or antigenically matched 
strains) using CDC-defined ILI definition. 
• 
First episode of RT-PCR confirmed US 
CDC-defined ILI that begins at least 14 days 
after vaccination through Day 181 
(Month 6)/end of influenza season caused by  
− 
Any influenza A or B strains; 
− 
Influenza A or B strains with similarity to 
vaccine strains; 

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Primary Objectives 
Primary Endpoints 
− 
Influenza A or B strains that are 
antigenically matched to vaccine strains. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 vaccine as compared to an 
active comparator against culture-confirmed 
influenza caused by any influenza A or B 
strains.  
• 
First episode of culture-confirmed protocol-
defined ILI that begins at least 14 days post 
vaccination through Day 181 (Month 6)/end of 
influenza season caused by any influenza A or 
B strains regardless of antigenic match to 
strains selected for the seasonal vaccine. 
• 
First episode of culture-confirmed CDC-
defined ILI that begins at least 14 days post 
vaccination through Day 181 (Month 6)/end of 
influenza season caused by any influenza A or 
B strains regardless of antigenic match to 
strains selected for the seasonal vaccine. 
• 
To evaluate relative vaccine efficacy of 
mRNA-1010 as compared to an active 
comparator to prevent hospitalizations 
associated with influenza illness. 
• 
Hospitalizations associated with RT-PCR 
confirmed protocol defined ILI that begins at 
least 14 days post vaccination through Day 181 
(Month 6)/end of influenza season caused by 
any strain of influenza virus regardless of 
antigenic match to the strains selected for the 
seasonal vaccine. 
• 
To evaluate the humoral immunogenicity of 
mRNA-1010 relative to that of an active 
comparator against vaccine-matched 
influenza A and B strains at Day 29 in a 
subset of participants. 
• 
GMT at Day 29 as measured by HAI assay. 
• 
Proportion of participants reaching 
seroconversion at Day 29 as measured by HAI 
assay. 
• 
The proportion of participants with a titer 
≥ 1:40 at Day 29 as measured by HAI assay. 
• 
GMFR comparing Day 29 to Day 1 (Baseline) 
as measured by HAI assay. 
Exploratory Objectives (may be performed) 
• 
To evaluate relative vaccine efficacy of mRNA-1010 as compared to an active comparator to 
prevent the following events that begin at least 14 days post vaccination through Day 361 
(Month 12)/EoS: 
− 
All-cause pneumonia. 
− 
Pneumonia-related hospitalization. 
− 
All-cause hospitalization. 
− 
Influenza-related mortality. 
− 
All-cause mortality. 
• 
To evaluate relative vaccine efficacy of mRNA-1010 as compared to an active comparator to 
prevent the following events that begin at least 14 days post vaccination through Day 361 
(Month 12)/EoS: 

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Primary Objectives 
Primary Endpoints 
− 
Exacerbation of cardiorespiratory diseases (eg, CHF, COPD, asthma, and other chronic 
cardiorespiratory diseases). 
− 
Cardiorespiratory hospitalizations and death. 
• 
To characterize the effect of mRNA-1010 as compared to an active comparator on other health 
outcomes including: 
− 
Number and frequency of participants aged 65 years and older with first episode of RT-PCR 
confirmed protocol-defined ILI by baseline frailty status. 
− 
EQ-5D-5L health questionnaire utility score at regular intervals as well as for participants with 
ILI. 
− 
WPAI:ILI impairment percentages for absenteeism, presenteeism, work productivity loss, and 
activity impairment for participants with ILI. 
• 
To characterize the effect of mRNA-1010 as compared to an active comparator on prevention or 
mitigation of the following that are associated with RT-PCR-confirmed ILI or all-cause 
pneumonia: 
− 
Healthcare encounters (outpatient visits, emergency department visits, and hospitalizations). 
− 
Duration of hospital encounters including intensive care unit hospitalization, and endotracheal 
intubation/mechanical ventilation. 
− 
Prescriptions for medications (antibiotics, antivirals, antipyretics, analgesics, and non-steroidal 
anti-inflammatory drugs). 
• 
Economic Analysis: A separate economic analysis is planned to estimate the impact of vaccination 
with mRNA-1010 on QoL-adjusted survival and on healthcare costs in real-world practice in one 
or more geographies. If performed, this analysis would use information on clinical, QoL, and 
resource use outcomes collected within the study to estimate QoL and costs to a healthcare payer 
comparing a strategy of vaccination with mRNA-1010 vs. an active comparator. This analysis 
would be conducted under a separate analysis plan and is intended for submission to health 
technology assessment and payer audiences to support use of mRNA-1010 following launch. 
Abbreviations: AE = Adverse events; AESI = Adverse events of special interest ARs = Adverse reactions; 
CDC = Centers for Disease Control and Prevention; CHF = Congestive heart failure; COPD = Chronic obstructive 
pulmonary disease; EoS = End of Study; EQ-5D-5L = EuroQoL-5 Dimension 5-Levels; GMFR = Geometric mean 
fold rise; GMT = Geometric mean titer; HAI = Hemagglutination inhibition; ILI = Influenza-like illness; 
MAAEs = Medically attended AEs; QoL = Quality of life; RT-PCR = Reverse transcriptase polymerase chain 
reaction; SAE = Serious adverse events; US = United States; WPAI:ILI = Work productivity and activity 
impairment questionnaire: Influenza-like illness. 
a. 
Similarity to strains selected for the seasonal vaccine: based on antigenicity testing and/or genomic sequencing. 
b. 
Antigenically matched to strains selected for the seasonal vaccine based on antigenicity testing. 

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4. 
STUDY DESIGN 
4.1. 
General Design 
This study will be a Phase 3, randomized, observer-blinded, active-controlled trial to evaluate the 
safety and efficacy in preventing seasonal influenza of mRNA-1010 in adults 50 years and older. 
The vaccine to be tested includes mRNAs encoding for the surface glycoproteins of the strains 
recommended by the WHO for 2022-2023 NH cell- or recombinant-based vaccines: 
• A/Wisconsin/588/2019 (H1N1)pdm09-like virus; 
• A/Darwin/6/2021 (H3N2)-like virus; 
• B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and 
• B/Phuket/3073/2013 (B/Yamagata lineage)-like virus. 
Immunizations are planned during the typical 2022/2023 NH vaccination campaign period. 
However, if the targeted number of reverse transcriptase-polymerase chain reaction (RT-PCR)-
confirmed ILI cases observed are not reached, an extension of enrollment over multiple influenza 
seasons may be required. As a result, vaccines with other seasonal-specific compositions may be 
used and administered during the relevant typical vaccination campaigns, as appropriate. 
Additionally, if the interim vaccine effectiveness analyses by public health authorities 
demonstrate noneffectiveness of licensed influenza vaccines, sample size re-estimation and 
continuation of enrollment into the next season may be considered. 
Approximately 23,000 participants will be randomized in a 1:1 ratio to receive a single dose of 
mRNA-1010 at 
 µg total mRNA or a single dose of the active comparator. Randomization will 
be stratified by age categories (≥ 50 to < 65 years or ≥ 65 years) and influenza vaccine status in 
the previous influenza season (received or not received) at the time of screening. At least 50% of 
enrollees will be ≥ 65 years old, including at least 10% who will be ≥ 75 years old. 
Table 3: 
Vaccination Groups and Dose Levels 
Vaccination 
Group 
Vaccination 
Received 
mRNA/Antigen 
Total Dose (µg) 
Number of 
Participants 
HA (each) (µg) 
1 
mRNA-1010 
 (of mRNA) 
 (of mRNA) 
11,500 
2 
Active 
Comparator 
(Fluarix®) 
 (of protein) 
 (of protein) 
11,500 
Abbreviations: HA = hemagglutinin; mRNA = messenger ribonucleic acid. 
Clinic visits for all participants will comprise a Screening visit (up to 28 days before the Day 1 
visit, or maybe on the same day as the Vaccination Visit on Day 1) and a Vaccination Visit 
(Day 1) as showed in the schedule of events (SoE, Table 1). 
For participants aged 65 years and older, frailty will be assessed by clinic staff at baseline using 
the Edmonton Frail Scale (EFS). 
Approximately 1000 participants will be asked to provide blood samples at baseline and on 
Day 29 (28 days post vaccination) for assessment of immune responses to the study intervention 
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(immune response biomarker subset). A clinic visit on Day 29 will be required for these 
participants. All participants will be asked to complete an electronic diary (eDiary) for solicited 
ARs from Day 1 to Day 7. All participants will be asked to provide an optional blood sample for 
future research use at Day 1. 
There will be 6 safety telephone call visits at Days 8, 29 (expect for those participants who are 
not in the immune response biomarker subset which requires a clinic visit on Day 29), 91, 181, 
271, and 361 (Month 12)/EoS as specified in the SoE. The study duration (including screening) 
is up to 13 months for each participant and the total study duration is approximately 27 months 
(if 2 influenza seasons are required to perform efficacy analyses). 
Participants will be instructed to report whether ILI symptoms have been experienced, via a 
Symptom Reporting eDiary, twice weekly from Day 1 to Day 181 and once weekly from 
Day 182 to Day 361 (Month 12)/EoS. If participants experience ILI symptoms, they will be 
instructed to enter the details in the eDiary and contact the clinic to determine if an NP swab 
should be collected for RT-PCR testing. NP swabs for testing should be collected within 72 
hours of symptom onset. Sites should also reach out to participants if illness symptoms are noted 
upon review of the eDiary to assess whether the participant is required to provide an NP swab. 
NP swab should be collected prior to any antiviral therapy if possible. NP swabs may be 
collected as part of a home visit in lieu of a clinic visit. In the event that NP swabs during ILI 
cannot be collected, any available influenza testing results performed outside of the study should 
be captured in the electronic case report form (eCRF). 
Unscheduled clinic visits for ILI symptoms and viral respiratory panel testing may be conducted. 
Participants who manifest protocol-defined ILI or for those participants who experience ILI 
symptoms but have not yet fulfilled protocol-defined ILI, and based on Investigator’s discretion 
when influenza is suspected, will be evaluated by real-time RT-PCR testing of NP swab 
specimen(s) for influenza and other respiratory pathogens. NP swabs may be collected as part of 
a home visit in lieu of a clinic visit. 
All participants who report symptoms of ILI will receive eDiary prompts to complete patient-
reported outcome questionnaires for EuroQoL 5 Dimension 5-Level (EQ-5D-5L) and Work 
Productivity and Activity impairment Questionnaire: Influenza-like Illness (WPAI:ILI). 
The Investigator might ask a participant to return to the clinical site for an unscheduled visit 
under certain situations (eg, if an AE is reported). Additional assessments, as necessary, may be 
conducted at these visits to ensure the safety and well-being of participants during the study. 
Electronic case report forms should be completed for each unscheduled visit. 
All personnel involved in the conduct of the study will remain blinded to individual treatment 
assignment until planned study unblinding, except for appropriately delegated unblinded 
pharmacists, vaccine administrators, and monitors. The participant, Investigator, and clinical 
staff responsible for study assessments/safety will not have access to the treatment assignment 
during the conduct of the study. The Investigator may be unblinded in the event of an emergency 
(refer to Section 6.3.7). 

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4.2. 
Scientific Rationale for Study Design 
This trial is designed as an observer-blind trial. Participants will receive a single dose of either 
mRNA-1010 vaccine or a licensed quadrivalent seasonal influenza vaccine (an active 
comparator) in order to assess safety and efficacy of the vaccine. 
In this observer-blind trial, participants, clinic staff involved in participant assessment, and 
Sponsor personnel (or its designees) will be blinded to participant vaccine allocation. A limited 
number of Sponsor and/or contract research organization (CRO) personnel will be unblinded to 
conduct safety data analyses for the DSMB safety data reviews (as described in the DSMB 
charter) and perform the primary analysis. Unblinded study personnel, who will not participate in 
any other aspect of the trial, will perform study intervention accountability, dose preparation, and 
study intervention administration. 
The NP swab specimen(s) for assessment of pathogens, including influenza virus and severe 
acute respiratory syndrome coronavirus 2 (SARS-CoV-2), will be collected any time from Day 1 
through Day 361 (Month 12)/EoS if the participants have protocol-defined ILI (see 
Section 8.10.5) or if deemed necessary per Investigator’s discretion when influenza is suspected. 
If participants experience these signs or symptoms, they will be instructed to contact the clinic to 
determine if an NP swab is required to be collected for testing. NP swabs may be collected as 
part of a home visit in lieu of a clinic visit. If NP swabs during ILI cannot be collected, any 
available influenza testing results performed outside of the study should be captured in the 
eCRF. 
4.3. 
Justification for Dose, Control Product, and Choice of Study 
Population 
The selection of the 
 µg dose level of mRNA-1010 is supported by the data from the Phase 1/2 
and the Phase 2 NH interim analyses. First, the 
 µg dose level elicited strong HAI antibody 
responses. The geometric mean titers (GMTs) exceeded the 1:40 titer threshold for the 2 
influenza A strains and 2 influenza B strains tested. This threshold was previously correlated 
with a 50% reduction in risk of influenza virus infection. This dose generated robust HAI 
responses for H1N1 and H3N2 strains with Day 29 GMTs that were higher than the licensed 
comparator. Second, the 
 µg dose level demonstrated an acceptable reactogenicity and safety 
profile. The frequencies of solicited ARs were lower in the 
 µg dose level than those of the 
 µg and 
 µg dose levels while the immunogenicity was comparable. The reactogenicity 
and safety profile of the 
 µg dose level was not substantially different to that of the 
 µg dose 
level, whereas the immunogenicity was higher particularly for adults 50 years and older. In 
summary, the safety and immunogenicity profile observed from the mRNA-1010-P101 study 
supports selecting mRNA-1010 at a 
 µg dose level for this study. Further details are provided 
in the IB. 
Fluarix is selected as an active control because it is licensed for the prevention of influenza 
disease in the adult population in the countries that will take part in this study. Enhanced 
quadrivalent influenza vaccines have not been considered for the ≥ 65 years old age group 
because they are not licensed or preferentially recommended in all participating countries.  
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Improved vaccine efficacy in adults ≥ 50 years old is needed given the increased morbidity and 
mortality in this population due to declining immunocompetence and increased burden of 
comorbid medical conditions. 
4.4. 
End of Study Definition 
A participant is considered to have completed the trial if they complete the final visit on Day 361 
(Month 12) as shown in the SoE (Table 1). 
The end of study is defined as completion of the last visit of the last participant in the trial or last 
scheduled procedure as shown in the SoE for the last participant in the trial globally. 

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5. 
STUDY POPULATION 
Approximately 23,000 participants will be enrolled. 
Prospective approval of protocol deviations to recruitment and enrollment criteria, also known as 
protocol waivers or exemptions, is not permitted. 
5.1. 
Inclusion Criteria 
Participants are eligible to be included in the study only if all the following criteria apply: 
1. At least 50 years of age at the time of consent (Screening visit). 
2. Investigator has assessed that the participant understands and is willing and physically 
able to comply with protocol-mandated follow-up, including all procedures. 
3. Provide written informed consent for participation in this study, including all evaluations 
and procedures as specified by this protocol. 
4. Females of nonchildbearing potential may be enrolled in the study. Nonchildbearing 
potential is defined as postmenopausal or permanently sterilized. Follicle-stimulating 
hormone may be measured at the discretion of the Investigator to confirm 
postmenopausal status (see additional information in Section 11.2). 
5. Females of childbearing potential may be enrolled in the study if the participant fulfills 
all the following criteria: 
− Has a negative pregnancy test at the Screening visit and on the day of vaccination 
prior to study vaccine dose being administered on Day 1. 
− Has practiced adequate contraception or has abstained from all activities that 
could result in pregnancy for at least 28 days prior to the first dose (Day 1). 
Adequate female contraception is defined as consistent and correct use of a local 
health authority-approved contraceptive method in accordance with the product 
label. 
− Has agreed to continue adequate contraception through 90 days following study 
vaccine administration. 
5.2. 
Exclusion Criteria 
Participants are excluded from the study if any of the following criteria apply: 
1. Close contact with someone with laboratory-confirmed influenza infection or with 
someone who has been treated with antiviral therapies for influenza (eg, Tamiflu®) 
within the past 5 days prior to the screening visit. 
2. Close contact with someone with SARS-CoV-2 infection or COVID-19 as defined by the 
US CDC or has had a positive SARS-CoV-2 test in the past 10 days prior to the 
Screening visit. 
3. Acutely ill or febrile (temperature ≥ 38.0°C [100.4°F]) 72 hours prior to or at the 
Screening visit or Day 1. Participants meeting this criterion may be rescheduled within 
the 28-day screening window and will retain their initially assigned participant number. 

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4. History of a diagnosis or condition that, in the judgment of the Investigator, is clinically 
unstable or may affect participant safety, assessment of safety endpoints, assessment of 
immune response, or adherence to study procedures. Clinically unstable is defined as a 
diagnosis or condition requiring significant changes in management or medication within 
the 60 days prior to the Screening visit and includes ongoing workup of an undiagnosed 
illness that could lead to a new diagnosis or condition. 
5. Reported history of congenital or acquired immunodeficiency, immunocompromising/ 
immunosuppressive condition, asplenia, or recurrent severe infections. The following 
conditions are permitted at the discretion of the Investigator: 
− Human immunodeficiency virus [HIV] positive participants on antiretroviral 
therapy with cluster of differentiation 4 count ≥ 350 cells/mm3 and HIV RNA 
≤ 500 copies/mL within the past 12 months. 
− Immune-mediated diseases that are stable, for example, Hashimoto's thyroiditis 
and type 1 diabetes mellitus or conditions such as asthma, psoriasis, vitiligo, gout, 
alopecia areata, autoimmune ovarian failure that do not require systemic 
immunosuppressants per Exclusion Criterion 10. 
6. Dermatologic conditions that could affect local solicited AR assessment of the injection 
site (eg, tattoos, vitiligo or psoriasis patches affecting skin over the deltoid area of the 
injection site). 
7. Reported history of anaphylaxis or severe hypersensitivity reaction after receipt of any 
mRNA or influenza vaccines or any components of the mRNA or influenza vaccines, 
including egg protein. 
8. Reported history of coagulopathy or bleeding disorder that is considered a 
contraindication to IM injection or phlebotomy. 
9. Any medical, psychiatric, or occupational condition, including reported history of 
substance abuse, that, in the opinion of the Investigator, may pose additional risk due to 
participation in the study or that could interfere with the interpretation of study results. 
10. Received systemic immunosuppressants for > 14 days in total within 180 days prior to 
the Screening visit (for glucocorticosteroids, ≥ 10 mg/day of prednisone or equivalent) or 
is anticipating the need for systemic immunosuppressive treatment at any time during 
participation in the study. Inhaled, nasal, intra-articular, and topical steroids are allowed. 
11. Received any vaccine authorized or approved by local health agency ≤ 28 days prior to 
study intervention (Day 1) or plans to receive a vaccine authorized or approved by local 
health agency within 28 days before or after the study intervention. 
12. Plans to receive a nonstudy influenza vaccine during the study from Day 1 to Day 181. 
13. Is unaware whether they received an influenza vaccine in the previous influenza season. 
14. Received a seasonal influenza vaccine or any other investigational influenza vaccine 
within 180 days prior to the Randomization Visit. 
15. Tested positive for influenza by local health authority-approved testing methods within 
180 days prior to the Randomization Visit. 

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16. Has been treated with antiviral therapies for influenza (eg, Tamiflu) within 180 days prior 
to the Randomization Visit. 
17. History of myocarditis, pericarditis, or myopericarditis within 60 days prior to the 
Screening visit. Participants who have not returned to baseline after their convalescent 
period will also be excluded. 
18. History of Guillain-Barre syndrome. 
19. Received systemic immunoglobulins and long-acting biological therapies that affect 
immune responses (eg infliximab) or blood products within 90 days prior to the 
Screening visit or plans to receive them during the study. 
20. Donated ≥ 450 mL of blood products within 28 days prior to the Screening visit or plans 
to donate blood products during the study. 
21. Participated in an interventional clinical study within 28 days prior to the Screening visit 
based on the medical history interview or plans to do so while participating in this study. 
Note: interventions such as counseling, biofeedback, and cognitive therapy are not 
exclusionary. 
22. Participant is working or has worked as study personnel or is an immediate family 
member or household member of study personnel, study site staff, or Sponsor personnel. 
5.3. 
Lifestyle Restrictions 
Participants must not eat or drink anything hot or cold within 10 minutes before oral temperature 
is taken. Participants in the trial should defer vaccination with licensed seasonal influenza 
vaccine until after completion of the Day 181 visit, if seasonal influenza vaccine is available, and 
they have discussed with the Investigators and have chosen to receive it. 
5.4. 
Screen Failures 
Screen failures are defined as participants who consent to participate in the clinical trial but are 
not subsequently randomized. A minimal set of screen failure information is required to ensure 
transparent reporting of screen failure participants to meet the Consolidated Standards of 
Reporting Trials (CONSORT) publishing requirements and to respond to queries from regulatory 
authorities. Minimal information includes date of informed consent, demography, screen failure 
details, eligibility criteria, and information on any SAE, which may have occurred from the time 
informed consent was obtained to the time of withdrawal. 
Individuals who do not meet the criteria for participation in this study (screen failures) may be 
rescreened 1 time if they will be eligible upon rescreening. 

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6. 
STUDY TREATMENT 
Study interventions are all pre-specified, investigational and non-investigational medicinal 
products, medical devices and other interventions (eg, surgical and behavioral) intended to be 
administered to the study participants during the study conduct. 
6.1. 
Study Intervention(s) Administered 
All mRNAs are formulated in LNPs composed of 4 lipids (1 proprietary and 3 commercially 
available) and provided as a sterile liquid for injection, white-to-off-white dispersion in 
appearance, at a concentration of 
 mg/mL 
 
. 
mRNA-1010 will be administered as a single IM injection dose at mRNA total dose level of 
 µg (see Table 4). 
The active comparator administered in this study is a licensed quadrivalent inactivated seasonal 
influenza vaccine administered as a single IM injection (see Table 4). 
Table 4: 
Study Interventions
Vaccination Group 
Investigational Vaccine 
Active Comparator 
Intervention Name 
mRNA-1010 
Fluarix®/Influsplit® 
Type 
Vaccine 
Vaccine 
Unit Dose Strength 
 µg (mRNA) 
 µg (protein) 
Dosage Level 
Single dose of 
 mL 
Single dose of 
 mL 
Route of 
Administration 
IM 
IM 
Physical Description 
Sterile liquid for injection, white to 
off white dispersion 
Sterile, colorless, and slightly 
opalescent suspension 
Source 
Provided centrally by the Sponsor 
Hybrid – Potentially Centrally and 
Locally 
Packaging and 
Labeling 
mRNA-1010 will be provided in 
2R glass vials. Each vial will be 
labeled as required per country 
requirement. 
Active comparator will be provided 
in a prefilled syringe in a carton. 
Each carton will be labeled as 
required per country requirement. 
Abbreviations: IM = intramuscular; mRNA = messenger ribonucleic acid. 
6.2. 
Randomization and Blinding 
Randomization will be performed using an Interactive Response Technology (IRT) system. 
Approximately 23,000 participants will be randomized in a 1:1 ratio to receive a single dose of 
mRNA-1010 at 
 µg total mRNA or a single dose of the active comparator (Table 3). 
Randomization will be stratified by age categories (≥ 50 to < 65 years or ≥ 65 years) and 
influenza vaccine status in the previous influenza season (received or not received) at the time of 
screening. At least 50% of enrollees will be ≥ 65 years old, including at least 10% who will be 
≥ 75 years old. 
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As the appearance of the study interventions differ, enrollment will be observer blinded to the 
treatment assignment. 
Dose preparation, administration, and accountability will be performed by designated unblinded 
site personnel who will not participate in any of the clinical study evaluations. The unblinded site 
personnel will prepare the dose out of view of the participant and the blinded site personnel. 
The laboratory personnel in charge of immunogenicity testing will be blinded to the treatment 
assignment of the samples tested throughout the course of the study. 
Except in the case of medical emergency, a participant’s treatment should not be unblinded 
without the approval of the Sponsor. The treatment code should be broken only if the 
Investigator in charge of the participant feels that the case cannot be treated without knowing the 
identity of the study intervention. Instructions regarding emergency unblinding will be provided 
to the Investigator and are discussed in Section 6.3.7. 
The Investigator, clinic staff, study participants, site monitors, and Sponsor personnel (or its 
designees) will be blinded to the study intervention administered until the study database is 
locked and unblinded for the final analysis. At the interim analyses (see Section 9.6.1), pre-
identified Sponsor team members and selected CRO team members will be unblinded to conduct 
the analyses. Study sites will remain blinded. 
6.3. 
Preparation/Handling/Storage/Accountability 
6.3.1. 
Clinical Study Material Preparation 
The study intervention will be prepared for each participant based on their vaccination group 
assignment. Details of the study interventions are provided in Table 4. Specific instructions for 
the preparation of mRNA-1010 and active comparator are contained in the Pharmacy Manual. 
6.3.2. 
Clinical Study Material Administration 
mRNA-1010 or the active comparator will be administered as a single IM injection into the 
deltoid muscle in adult participants on Day 1. The study intervention should be administered 
preferably into the nondominant arm. The dose volume will be held constant at approximately 
 mL per injection. 
Participants will be monitored for at least 30 minutes after administration of the study 
intervention. Assessments will include vital sign measurements and monitoring for local or 
systemic reactions as shown in the SoE (Table 1). 
The clinic will be appropriately staffed with individuals with basic cardiopulmonary 
resuscitation training/certification. Either onsite resuscitation equipment and personnel or 
appropriate protocols for the rapid transport of a participant to a resuscitation area or facility are 
required. 
Further instructions for the preparation and administration of mRNA-1010 and active comparator 
are described in the Pharmacy Manual. 
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6.3.3. 
Clinical Study Material Packaging and Labeling 
The Sponsor will provide the Investigator (via the clinic pharmacy) with adequate quantities of 
the study intervention. The study intervention will have all required labeling per regulations and 
will be supplied to the pharmacy in an unblinded manner. 
All study interventions used in this study will be prepared, packaged, and labeled in accordance 
with the standard operating procedures of the Sponsor or those of its designee, Code of Federal 
Regulations (CFR) Title 21, GMP guidelines, International Council for Harmonisation (ICH) 
GCP guidelines, guidelines for Quality System Regulations, and applicable regulations. 
6.3.4. 
Clinical Study Material Storage 
mRNA-1010 must be stored at the clinical site at 2°C to 8°C in a secure area with limited access 
and must be protected from moisture and light until it is prepared for administration. The 
refrigerator should have automated temperature recording and a 24-hour alert system in place 
that allows for rapid response in case of refrigerator malfunction. The refrigerator should be 
connected to a backup generator. In addition, for study intervention accountability, site staff are 
required to keep a temperature log to establish a record of compliance with these storage 
conditions. The clinic is responsible for reporting any study intervention that was not 
temperature controlled during shipment or storage. Such study intervention will be retained for 
inspection by the monitor and disposed of according to approved methods. mRNA-1010 will be 
stored at -25°C to -15°C at the depots and during shipments to the clinical sites. 
The active comparator should be stored in its original container and in accordance with the 
instructions in the Pharmacy Manual. 
6.3.5. 
Clinical Study Material Accountability 
The Investigator is responsible for ensuring the study intervention accountability staff maintain 
an accurate record of the shipment receipt, the inventory at the site, dispensing of study 
intervention, and the return to the Sponsor or alternative disposition of used/unused product(s) in 
a drug accountability log. Drug accountability will be noted by the site monitor during site visits 
and at the completion of the study. For further direction, refer to the Pharmacy Manual. 
6.3.6. 
Clinical Study Material Handling and Disposal 
A site monitor will reconcile the clinical study material during study conduct and at the end of 
the study for compliance. Once fully reconciled at the site, the clinical study material can be 
destroyed at the investigational site or a Sponsor-selected third party, as appropriate. 
Clinical study material may be destroyed at the clinic only if permitted by local regulations and 
authorized by the Sponsor. A Certificate of Destruction must be obtained and sent to the Sponsor 
or designee. For further direction, refer to the Pharmacy Manual. 
6.3.7. 
Unblinding 
Except in the case of medical emergency, a participant’s treatment assignment should not be 
unblinded without the approval of the Sponsor. If a participant becomes seriously ill or pregnant 
during the study, the blind will be broken only if knowledge of the treatment assignment will 
affect that participant’s clinical management (see Section 11.6 for country-specific amendment 

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affecting this paragraph). In the event of a medical emergency requiring identification of 
individual treatment assignment, the Investigator must promptly contact the CRO clinical 
research associate to explain the need for unblinding within 24 hours of opening the code. The 
Investigator will be responsible for documenting the time, date, reason for unblinding, and the 
names of the personnel involved. The Investigator (or designee) will have access to unblind 
participants within IRT. All unblinding will be tracked via an audit trail in IRT and documented 
in the final study report. 
6.4. 
Study Intervention Compliance 
All study interventions will be administered by qualified and trained study personnel to ensure 
that all doses administered comply with those planned. Study vaccine administration will be 
recorded in the eCRF. Administration data will be reconciled with site accountability records to 
determine compliance. 
6.5. 
Concomitant Therapy 
At each visit, the site personnel should question the participant regarding any medications taken 
and vaccinations received and record the information as specified in Section 6.5.1.  
6.5.1. 
Recording of Concomitant Medications and Concomitant Vaccinations 
The following concomitant medications and vaccines must be recorded in the eCRF: 
• All non-study vaccinations administered within the period starting 28 days before the 
study intervention and through Day 361/EoS. 
• All concomitant medications taken through 28 days after the study intervention. 
Antipyretics and analgesics taken prophylactically (ie, taken in the absence of any 
symptoms in anticipation of an injection reaction) will be recorded as such. 
• Any authorized or investigational COVID-19 vaccine at any time before the study 
intervention. 
• Any authorized influenza vaccine administered since August 2021. 
• Systemic steroids (≥ 10 mg/day prednisone or equivalent), immunosuppressants, 
immunoglobulins and long-acting biological therapies that affect immune responses (eg 
infliximab), and/or blood products administered at any time during the study period after 
the study intervention. 
• Any concomitant medications relevant to or for the treatment of an SAE, AESI, or 
medically attended AE (MAAE) from Day 1 through Day 361 (Month 12)/EoS. 
• The participant will be asked to record in the eDiary if they have taken any antipyretic or 
analgesic to treat or prevent fever or pain within 7 days after the study intervention, 
including the day of injection. Reported antipyretic or analgesic medications should be 
recorded in the source document by the clinic staff during the clinic visits after 
vaccination or via other participant interactions (eg, telephone calls). 
Concomitant medications (including vaccinations) will be coded using the WHO Drug Global. 

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It is the Investigator’s responsibility to ensure that details regarding the concomitant medications 
are adequately recorded in the eCRF. 
6.5.2. 
Concomitant Medications and Vaccines that May Lead to the Elimination of a 
Participant from Per-Protocol Analyses 
The use of the following concomitant medications and/or vaccines will not require withdrawal of 
the participant from the study but may determine a participant’s evaluability in the Per-protocol 
(PP) Set. Analysis sets are described in Section 9.4. 
• Any investigational or nonregistered product (drug or vaccine) other than the study 
intervention used during the study period. 
• Immunosuppressants administered chronically (ie, more than 14 days in total) during the 
study period. For glucocorticosteroids, this will mean that prednisone ≥ 10 mg/day or the 
equivalent is not permitted. Inhaled, nasal, intra-articular, and topical steroids are 
allowed. 
• An authorized or licensed noninfluenza vaccine that is not adjuvanted administered 
within 14 days before or after the study intervention. 
• An authorized or licensed adjuvanted, noninfluenza vaccine administered within 28 days 
after the study intervention. 
• Any non-study influenza vaccine administered during the study period. 
• Immunoglobulins and long-acting biological therapies that affect immune responses (eg, 
infliximab) and/or any blood products administered during the study period. 
6.6. 
Continuous Access to Study Intervention After the End of the Study 
There will be no access to study intervention following the end of the study. 

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7. 
DELAY OR DISCONTINUATION OF STUDY INTERVENTION 
AND PARTICIPANT DISCONTINUATION/WITHDRAWAL 
7.1. 
Participant Discontinuation/Withdrawal from the Study 
Participants who withdraw or are withdrawn from the study will not be replaced. From an 
analysis perspective, a “withdrawal” from the study refers to a situation wherein a participant 
does not return for the final visit foreseen in the protocol. 
Participants can withdraw consent and withdraw from the study at any time, for any reason, 
without prejudice to further treatment the participant may need to receive. The Investigator will 
request that the participant complete all study procedures pending at the time of withdrawal. 
If a participant desires to withdraw from the study because of an AE, the Investigator will 
attempt to obtain agreement to follow-up with the participant until the event is considered 
resolved or stable and will then complete the EoS section of the eCRF. 
All data collected until the date of withdrawal or last contact of the participant will be used for 
the analysis. 
Information relative to the withdrawal will be documented in the eCRF. The Investigator will 
document whether the decision to withdraw a participant from the study was made by the 
participant, or by the Investigator, as well as which of the following possible reasons was 
responsible for withdrawal: 
• AE (specify) 
• SAE (specify) 
• Solicited AR or reactogenicity event (specify) 
• Death 
• Lost to follow-up 
• Physician decision (specify) 
• Pregnancy 
• Protocol violation 
• Study terminated by Sponsor 
• Withdrawal of consent by participant (specify) 
• Other (specify) 
Participants who are withdrawn from the study because of AEs (including SAEs or solicited 
ARs) must be clearly distinguished from participants who are withdrawn for other reasons. 
Investigators will follow-up with participants who are withdrawn from the study as a result of an 
AE, SAE, or solicited AR until resolution or stabilization of the event. 
If a participant withdraws from the study, they may request destruction of any samples taken and 
not tested, and the Investigator must document this in the site study records. 

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If the participant withdraws consent for disclosure of future information, the Sponsor may retain 
and continue to use any data collected before such a withdrawal of consent (see Section 11.1.6). 
The Sponsor will continue to retain and use all research results that have already been collected 
for the study evaluation. All biological samples that have already been collected may be retained 
and analyzed at a later date (or as permitted by local regulations). 
7.2. 
Lost to Follow up 
A participant will be considered Lost to Follow-up (LTFU) if the participant repeatedly fails to 
return for scheduled visits without stating an intention to withdraw consent and is unable to be 
contacted by the study site. The following actions must be taken if a participant fails to return to 
the clinic for a required study visit: 
• The site must attempt to contact the participant and reschedule the missed visit as soon as 
possible, counsel the participant on the importance of maintaining the assigned visit 
schedule and ascertain whether the participant wishes to and/or should continue in the 
study. 
• Before a participant is deemed lost to follow up, the Investigator or designee must make 
an effort to regain contact with the participant (where possible, 3 telephone calls and, if 
necessary, a certified letter to the participant’s last known mailing address or locally 
equivalent methods). These contact attempts (eg, dates of telephone calls and registered 
letters) should be documented in the participant’s medical record. 
• Should the participant continue to be unreachable, the participant will be considered to 
have withdrawn from the study.  
• A participant should not be considered LTFU until due diligence, as described above, has 
been completed. 

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8. 
STUDY ASSESSMENTS AND PROCEDURES 
The study SoE can be found in Table 1. 
Before performing any study procedures, all participants will sign an informed consent form 
(ICF Section 11.1.6). 
8.1. 
Screening 
At the Screening visit (up to 28 days before the Day 1 visit), all screening requirements, 
including the Screening Status eCRF to indicate if a participant is either a screen failure or not, 
must be completed. 
The Screening visit and Day 1 visit may be performed on the same day or a different day. 
Additionally, the Screening visit may be performed over multiple visits if within the 28-day 
screening window. 
8.2. 
Confirm Inclusion and Exclusion Criteria 
All inclusion and exclusion criteria described in Section 5.1 and Section 5.2 must be met before 
randomization (Day 1 visit). 
8.3. 
Demographic and Baseline Data 
Demographic information relating to the participant’s sex, age, ethnicity, and race will be 
recorded at Screening on the appropriate eCRF page. 
8.4. 
Medical History 
Medical history (including verbal history) from each participant will be collected and recorded 
on the appropriate eCRF page. Significant findings that were present prior to study vaccination 
must be included in the Medical History eCRF page. 
8.5. 
Randomization 
Study intervention group and study intervention assignment allocation will be performed on 
Vaccination Visit (Day 1) as described in Section 6.2. The confirmation for study vaccine 
administration must be recorded on the Injection eCRF page. 
8.6. 
Physical Examination and Vital Signs 
A full physical examination will be performed at the Screening visit (according to standard 
medical practice, including assessment of height and weight). Vital sign measurements must 
include the assessment of body temperature (oral being the preferred route), systolic and diastolic 
blood pressures, heart rate, and respiratory rate. The information collected will be recorded in the 
eCRF. 
Vital signs will be measured by study site staff at the Day 1 visit prior to vaccination and 
approximately 30 minutes after vaccination, prior to discharge of the participant. 

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Symptom-directed physical examinations will be performed at all other scheduled timepoints as 
specified in the SoE (Table 1). Interim physical examinations may be performed at the discretion 
of the Investigator. 
Vital signs may be collected at other clinic visits in conjunction with a symptom-directed 
physical examination. 
Treatment of any abnormality observed during physical examination should be performed 
according to local medical practice outside the study or by referral to an appropriate healthcare 
provider at the discretion of the Investigator. 
8.7. 
Study Vaccine Administration 
A single dose vaccination (mRNA-1010 or active comparator) will be administered to all 
participants. 
After completing all prerequisite procedures prior to vaccination, the study intervention will be 
administered via a single IM injection into the deltoid muscle. A detailed description of the 
vaccine administration procedure is provided in Section 6.3.2. 
The participants will be observed closely (via clinical assessment including measurement of vital 
signs) for at least 30 minutes following administration of the study intervention, with appropriate 
medical treatment readily available in case of anaphylaxis or other hypersensitivity reactions. 
8.8. 
Efficacy Assessments 
Assessment will be conducted to document RT-PCR-confirmed protocol-defined-ILI that begins 
at least 14 days post vaccination through Day 181 (Month 6)/end of influenza season caused by 
any influenza A or B virus strains or by strains similar to or antigenically matched to the strains 
selected for the seasonal vaccine. 
Participants who develop symptoms consistent with protocol-defined ILI will have NP swabs 
collected for testing and ILI symptoms assessed. The initial test on the NP swab will be a real-
time RT-PCR-based assay, to determine if either influenza A and/or B strains, as well as other 
respiratory viruses such as SARS-CoV-2, are present in the clinical sample. For samples that test 
positive for influenza in the RT-PCR assay, additional assays such as genetic sequencing of the 
virus genes and/or virus culture with subsequent antigenicity testing will be performed to 
determine vaccine match or similarity.  
8.9. 
Safety Assessments 
Safety assessments will include monitoring and recording of the following for each participant in 
the study: 
• Solicited local and systemic ARs (Section 8.10.3) that occur through the 7 days following 
the study intervention (ie, the day of injection and 6 subsequent days). Solicited ARs will 
be recorded daily using eDiary (Section 8.9.4). 
• Unsolicited AEs (Section 8.10.1) observed or reported through the 28 days following the 
study intervention (ie, the day of injection and 27 subsequent days). Unsolicited AEs are 
defined in Section 8.10.1. 

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• AEs leading to discontinuation from study participation from Day 1 through Day 361 
(Month 12)/EoS or withdrawal from the study. 
• MAAEs from Day 1 through Day 361 (Month 12)/EoS or withdrawal from the study. 
MAAEs are defined in Section 8.10.4. 
• AESIs from Day 1 through Day 361 (Month 12)/EoS or withdrawal from the study. 
AESIs are defined in Section 8.10.6. 
• SAEs from Day 1 through Day 361 (Month 12)/EoS or withdrawal from the study. SAEs 
are defined in Section 8.10.2. 
• Vital signs measurement. 
• Details of all pregnancies in female participants will be collected after the start of study 
intervention and until the end of their participation in the study (Section 8.9.5). All 
pregnancies must be followed to determine the outcome; however, pregnancy 
related-data received after the end of the study may not be collected in the clinical 
database. 
Planned time points for all safety assessments are provided in the SoE (Table 1). 
8.9.1. 
Pregnancy Screen and Testing 
A pregnancy test via point of care urine test will be performed for all female participants of 
childbearing potential at the Screening visit and before the vaccine dose on Day 1, if Day 1 is not 
on the same day as the Screening visit. At the discretion of the Investigator, a pregnancy test 
either via blood or point-of-care urine can be performed at any time. Additional pregnancy 
testing during the study may also be performed if required by local regulatory requirements. The 
participant’s FSH level may be measured at the Screening visit, as necessary, and at the 
discretion of the Investigator, to confirm postmenopausal status (Section 11.2). 
Further details on reporting and follow-up of pregnancy are provided in Section 8.9.5. 
8.9.2. 
Assessments for Respiratory Viral Infections 
The NP swab specimen(s) for pathogens, including influenza virus, will be collected any time 
from Day 1 to Day 361 (Month 12)/EoS if participants have protocol-defined ILI 
(Section 8.10.5) or if deemed necessary per Investigator’s discretion when influenza is 
suspected. If participants experience these signs or symptoms, they will be instructed to contact 
the clinic to determine if they need an NP swab collected for testing. NP swab collection should 
occur within 72 hours of symptom onset. Sites may follow up with participants for symptom 
review if illness symptoms are noted upon review of the Symptom Reporting eDiary to assess 
whether the participant is required to provide an NP swab. NP swab should be collected prior to 
any antiviral therapy, if possible. NP swabs may be collected as part of a home visit in lieu of a 
clinic visit. In the event that NP swabs during ILI cannot be collected, any available influenza 
testing results performed outside of the study should be captured in the eCRF. 
Participants who experience protocol-defined ILI (Section 8.10.5) must have NP swabs collected 
for RT-PCR testing of influenza virus and other respiratory pathogens. For participants who 
experience ILI symptoms but have not yet fulfilled protocol-defined ILI definition, Investigators 
may use their discretion to perform NP swabs when influenza is suspected. If Investigator 

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discretion is applied, participant should be followed-up for any new symptoms following NP 
swab collection.  
Symptoms reporting for ILI will be conducted between Day 1 through Day 361 (Month 12)/EoS 
as described in Section 8.9.4. 
All cases that meet the definition of RT-PCR-confirmed influenza infection should be captured 
as MAAEs along with relevant concomitant medications, hospitalizations, outpatient medical 
care, and details about severity, seriousness, and outcome. 
If an unscheduled visit for assessment of protocol-defined ILI occurs within the first 28 days post 
study injection, the event should be captured as an unsolicited AE on the Adverse Event eCRF 
page. If such an unscheduled visit occurs after Day 29, it should be captured as an AE only if it 
meets MAAE definition (additional medical evaluation, including examinations/testing not 
required per protocol, and/or treatment is provided during the visit) OR if the participant meets 
RT-PCR confirmed influenza infection (RT-PCR with positive result for influenza) 
(Section 8.10.5). 
8.9.3. 
Safety Telephone Calls 
A safety telephone call is a telephone call made to the participant by trained site personnel. This 
call will follow a script, which will facilitate the collection of relevant safety information. Safety 
telephone calls will follow a schedule for each participant, as shown in the SoE (Table 1). The 
participant will be interviewed according to the script about occurrence of AEs, MAAEs, SAEs, 
AESIs, AEs leading to withdrawal from study participation, concomitant medications associated 
with those events, and any nonstudy vaccinations. All safety information collected from the 
telephone contact must be documented in source documents as described by the participant and 
not documented on the script used for the safety telephone contact. An unscheduled follow up 
safety call may be triggered if an eDiary record results in identification of a relevant safety event. 
8.9.4. 
Use of Electronic Diaries 
At the time of consent, the participants must confirm they will be willing to complete an eDiary 
(for 7-day reactogenicity). The local and systemic ARs that will be solicited by the eDiary are 
described in Table 5. 
Solicited local and systemic reactogenicity ARs will be collected on the day of study intervention 
and during the 7 days after study intervention (ie, the day of dosing and 6 subsequent days). 
Details on the recording of local and systemic ARs are included in Section 8.10.3. 
At the dosing visit, participants will record data into the eDiary starting approximately 
30 minutes after dosing under supervision of the site staff to ensure successful entry of 
assessments. The 30-minute observation period is an opportunity for site staff to train the 
participant on eDiary completion requirements. The site staff will perform any retraining as 
necessary throughout the study. 
At the dosing visit, participants will be instructed on thermometer usage to measure body 
temperature, ruler usage to measure injection site erythema (redness) and swelling/induration 
(hardness), and self-assessment for localized axillary (underarm) swelling or tenderness 
ipsilateral (on the same side as the injection arm[s]) during the 7 days after study injection. Daily 

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oral temperature measurement should be performed at approximately the same time each day 
using the thermometer provided by the site staff. 
The participant will be trained on how to complete the eDiary questions according to the SoE 
(Table 1) and also reminded to call the site immediately if they experience any condition. If 
eDiary questions result in identification of relevant safety events according to the study period or 
symptoms of ILI, a follow-up call will be triggered. The results of the call should be recorded in 
the appropriate source documentation. 
If a participant does not respond to the eDiary questions according to the SoE, site staff will 
follow-up with the participant. 
8.9.5. 
Recording and Follow-up of Pregnancy  
The effects of mRNA-1010 on the unborn child and on the newborn baby are not known. 
Because of this, it is important that study participants are not pregnant and do not become 
pregnant during the course of the study. Female individuals who have a positive pregnancy test 
at the Screening visit should not be enrolled; participants who have a positive pregnancy test at 
Day 1 must not receive the study intervention and should be withdrawn from the study. Female 
participants who become pregnant at any time during the study after receiving the study 
intervention should be asked to remain in the study and be followed-up for safety. Pregnancy 
testing is scheduled to occur at the Screening visit and Day 1 (Table 1). Additional pregnancy 
testing during the study may also be performed if required by local regulatory requirements. 
Pregnancies reported in female participants will be collected after the start of study intervention 
and until Day 361 (Month 12)/EoS. 
• If a pregnancy is reported, the Investigator should inform the Sponsor within 24 hours of 
learning of the pregnancy and should follow the procedures outlined in this section. 
• Abnormal pregnancy outcomes (eg, spontaneous abortion, fetal death, stillbirth, 
congenital anomalies, ectopic pregnancy) are considered SAEs. 
Pregnancies occurring in participants after administration of study intervention must be reported 
to the Sponsor or designee within 24 hours of the site learning of its occurrence. If the participant 
agrees to submit this information, the pregnancy must be followed to determine the outcome, 
including spontaneous or voluntary termination, details of the birth, and the presence or absence 
of any birth defects, congenital abnormalities, or maternal and/or newborn complications. This 
follow-up should occur even if intended duration of the safety follow-up for the study has ended. 
Pregnancy report forms will be distributed to the study site to be used for this purpose. The 
Investigator must immediately (within 24 hours of awareness) report to the Sponsor any 
pregnancy resulting in an abnormal outcome according to the procedures described for SAEs. 
8.9.6. 
Recording and Follow-up of an AE and/or SAE 
The Investigator is responsible for ensuring that all AEs and SAEs are recorded in the eCRF and 
reported to the Sponsor. 
Solicited ARs will be collected from Day 1 through 7 days after the study intervention (ie, the 
day of injection and 6 subsequent days). Other (unsolicited) AEs will be collected from Day 1 
through 28 days after the study intervention (ie, the day of injection and 27 subsequent days). 

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MAAEs, SAEs, and AESIs will be collected from participants as specified in the SoE (Table 1) 
from Day 1 until the end of their participation in the study. 
At every clinic visit or telephone contact, participants will be asked a standard question to elicit 
any medically related changes in their well-being (including surveillance for respiratory viral 
infection symptoms) according to the scripts provided. Participants will also be asked if they 
have been hospitalized, had any accidents, used any new medications, changed concomitant 
medication regimens (both prescription and over-the-counter medications), or had any non-study 
vaccinations. 
In addition to participant observations, physical examination findings and other documents 
relevant to participant safety classified as an AE will be documented on the AE page of the 
eCRF. 
After the initial AE/SAE report, the Investigator is required to proactively follow each 
participant at subsequent visits/contacts. All AEs and SAEs will be treated as medically 
appropriate and followed until resolution, stabilization, the event is otherwise explained, or the 
participant is LTFU (as defined in Section 7.2). 
8.9.7. 
Reporting Adverse Events 
The Investigator is responsible for reporting all AEs that are observed or reported during the 
study, regardless of their relationship to the study intervention or their clinical significance. If 
there is any doubt as to whether a clinical observation is an AE, the event should be reported. 
All unsolicited AEs reported or observed during the study will be recorded on the AE page of the 
eCRF. Information to be collected includes, type of event, time of onset, Investigator-specified 
assessment of severity (impact on activities of daily living) and relationship to study 
intervention, time of resolution of the event, seriousness, as well as any required treatment or 
evaluations, and outcome. The unsolicited AEs resulting from concurrent illnesses, reactions to 
concurrent illnesses, reactions to concurrent medications, or progression of disease states must 
also be reported. All AEs will be followed until they are resolved or stable or judged by the 
Investigator to be not clinically significant. The Medical Dictionary for Regulatory Activities 
(MedDRA) will be used to code all unsolicited AEs. 
Refer to Section 8.9.9 for reporting of medical occurrences that begin before the start of study 
intervention administration but after obtaining informed consent. 
8.9.8. 
Reporting Serious Adverse Events 
Any AE considered serious by the Investigator or that meets SAE criteria (Section 8.10.2) must 
be reported to the Sponsor immediately (within 24 hours of becoming aware of the SAE). The 
Investigator will assess whether there is a reasonable possibility that the study intervention 
caused the SAE. The Sponsor will be responsible for notifying the relevant regulatory authorities 
of any SAE as outlined in the 21 US CFR Parts 312 and 320. The Investigator is responsible for 
notifying the institutional review board (IRB) or independent ethics committee (IEC) directly. 
If the eCRF is unavailable at the time of the SAE, the paper SAE/AESI Report Form distributed 
to the study sites should be completed and sent via email or fax as provided on the form.  
Regulatory reporting requirements for SAEs are described in Section 8.9.11. 

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The Investigator and any qualified designees are responsible for detecting, documenting, and 
recording events that meet the definition of an AE, including SAEs, and remain responsible for 
following up AEs that are serious, considered related to the study intervention or study 
procedures, or that caused the participant to discontinue the study. 
8.9.9. 
Time Period and Frequency for Collecting AE and SAE Information 
Medical occurrences that begin before the start of study intervention administration but after 
obtaining informed consent will be recorded in the Medical History/Current Medical Conditions 
section of the eCRF and not in the AE section; however, if the condition worsens at any time 
after study intervention administration, it will be recorded and reported as an AE. 
Adverse events may be collected as follows: 
• Observing the participant. 
• Receiving an unsolicited complaint from the participant. 
• Questioning the participant in an unbiased and nonleading manner. 
All SAEs will be recorded and reported to the Sponsor or designee immediately and under no 
circumstance should this exceed 24 hours of becoming aware of the event, as indicated in 
Section 8.10.2. The Investigator will submit any updated SAE data to the Sponsor within 24 
hours of it being available. 
Investigators are not obligated to actively seek AEs or SAEs after conclusion of the study 
participation (EoS). However, if an Investigator learns of any SAE, including a death, at any 
time after a participant has been discharged from the study and considers the event to be 
reasonably related to the study intervention or study participation, the Investigator must promptly 
notify the Sponsor. 
8.9.10. 
Method of Detecting AEs and SAEs 
eDiary has specifically been designed for this study by the Sponsor to collect solicited ARs. 
Refer to Section 8.9.4 for further details on the use of eDiary. Details on recording of solicited 
ARs in an eDiary are included in Section 8.10.3. 
The Investigator is responsible for the documentation of AEs regardless of vaccination group or 
suspected causal relationship to the study intervention. For all AEs, the Investigator must pursue 
and obtain information adequate to determine the outcome of the AE and to assess whether the 
AE meets the criteria for classification as an SAE or AESI requiring immediate notification to 
the Sponsor or its designated representative. 
Care will be taken not to introduce bias when detecting AEs and/or SAEs. Open ended and 
nonleading verbal questioning of the participant is the preferred method to inquire about AE 
occurrences. 
8.9.11. 
Regulatory Reporting Requirements for SAEs 
Prompt notification by the Investigator to the Sponsor of a SAE is essential so that legal 
obligations and ethical responsibilities towards the safety of participants and the safety of a study 
intervention under clinical investigation are met. 

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The Sponsor has a legal responsibility to notify both the local regulatory authority and other 
regulatory agencies about the safety of a study intervention under clinical investigation. The 
Sponsor will comply with country-specific regulatory requirements relating to safety reporting to 
the regulatory authority, IRB/IEC, and Investigators. 
Safety reports must be prepared for suspected unexpected serious adverse reactions and will be 
forwarded to Investigators according to local regulatory requirements and Sponsor policy. 
An Investigator who receives a safety report describing an SAE or other specific safety 
information (eg, summary or listing of SAEs) from the Sponsor will review and then file it along 
with the IB and will notify the IRB/IEC, if appropriate according to local requirements. 
8.9.12. 
Blood Sampling Volumes 
The maximum amount of blood collected from each participant over the duration of the study, 
including any extra assessments that may be required, will not exceed blood limits specified in 
the ICF. Repeat or unscheduled samples may be taken for safety reasons or for technical issues 
with the samples. Further details are provided in both the ICF and Laboratory Reference Manual. 
8.9.13. 
Ancillary Supplies for Participant Use 
Clinics will distribute Sponsor-provided oral thermometers and rulers for use by participants in 
assessing body temperature and injection site reactions for recording solicited ARs in the eDiary. 
8.10. 
Safety Definitions 
8.10.1. 
Adverse Event 
An AE is defined as any untoward medical occurrence associated with the use of a drug in 
humans, whether or not considered drug related.  
A treatment-emergent AE (TEAE) is defined as any event not present before exposure to the 
study intervention or any event already present that worsens in intensity or frequency after 
exposure.  
Events Meeting the Adverse Event Definition 
• Exacerbation of a chronic or intermittent pre-existing condition including either an 
increase in frequency and/or intensity of the condition. 
• New conditions detected or diagnosed after the first dose of study intervention even 
though they may have been present before the start of the study. 
Events NOT Meeting the Adverse Event Definition 
• Procedures planned before study entry (eg, hospitalization for preplanned surgical 
procedure). 
• Medical or surgical procedure (eg, endoscopy, appendectomy) - the condition that leads 
to the procedure should be the AE. 
• Situations in which an untoward medical occurrence did not occur (social and/or 
convenience admission to a hospital). 

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An unsolicited AE is any AE reported by the participant that is not specified as a solicited AR 
(Section 8.10.3) in the protocol; or is specified as a solicited AR in the protocol, but starts 
outside the protocol-defined period for reporting solicited ARs (ie, for the 7 days after each dose 
of the study intervention).  
8.10.2. 
Serious Adverse Events 
An AE (including a solicited AR) is considered a SAE if it results in any of the following 
outcomes:  
• Results in Death 
• Is life-threatening  
An AE is considered life-threatening if, in the view of either the Investigator or the 
Sponsor, its occurrence places the participant at immediate risk of death. It does not 
include an AE that, had it occurred in a more severe form, might have caused death. 
• Inpatient hospitalization or prolongation of existing hospitalization 
In general, inpatient hospitalization indicates the participant was admitted to the hospital 
or emergency ward for at least 1 overnight stay as an inpatient for observation and/or 
treatment that would not have been appropriate in the physician’s office or outpatient 
setting. Complications that occur during inpatient hospitalization will be recorded as an 
AE; however, if a complication/AE prolongs hospitalization or otherwise fulfills SAE 
criteria, the complication/AE will be recorded as a separate SAE. 
• Persistent or significant disability or incapacity or substantial disruption of the 
ability to conduct normal life functions 
This definition is not intended to include experiences of relatively minor medical 
significance such as uncomplicated headache, nausea/vomiting, diarrhea, influenza, and 
accidental trauma (eg, sprained ankle) which may interfere with or prevent everyday life 
functions but do not constitute a substantial disruption (see Section 11.6 for country-
specific amendment affecting this paragraph). 
• Congenital anomaly or birth defect 
• Medically important event  
An AE is medically important if, per the medical judgment of the Investigator or the 
Sponsor, it is determined that SAE reporting is appropriate in other situations, such as 
important medical events that may not be immediately life-threatening or result in death 
or hospitalization, but may jeopardize the participant or require medical or surgical 
intervention to prevent one of the other outcomes listed in the above definition.  

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8.10.3. 
Solicited Adverse Reactions  
Solicited ARs are a subset of AEs consisting of selected signs and symptoms that participants are 
asked to record/report. In this study, the solicited ARs are reactogenicity events. The term 
“reactogenicity” refers to the occurrence of transient adverse effects associated with vaccine 
administration. An eDiary will prompt daily participant reporting of solicited ARs using a 
structured checklist (Section 8.9.4). Participants will record such occurrences in the eDiary on 
the day of administration of study intervention and on each of the 6 days after dosing. 
Severity grading of reactogenicity events will be automatically assigned upon participant entry 
into the eDiary based on the grading scales presented in Table 5, which are modified from the 
Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventative 
Vaccine Clinical Trials (DHHS 2007). All solicited ARs (local and systemic) will be considered 
causally related to dosing. 
If a participant reports a solicited AR with onset during the solicited period, but they did not 
record the event in the eDiary, then the event should be recorded by study staff on the 
Reactogenicity page of the eCRF. 
If the event starts during the solicited period, but continues beyond 7 days after dosing, the 
participants should notify the site to provide an end date and close out the event on the 
Reactogenicity page of the eCRF. 
If the participant reported an event that started after the solicited period (ie, after Day 7), it 
should be recorded as an AE on the AE page of the eCRF. Causality for these events will be 
determined per assessment by the Investigator. 
Any solicited AR that meets any of the following criteria must be entered into the participant’s 
source document and must also be recorded by the study site staff in the solicited AR section of 
the participant’s eCRF:  
• Solicited AR that results in a visit to a healthcare practitioner (HCP) (MAAE).  
• Solicited AR leading to the participant withdrawing from the study or the participant 
being withdrawn from the study by the Investigator (AE leading to withdrawal). 
• Solicited AR lasting beyond 7 days post injection. 
• Solicited AR that otherwise meets the definition of an SAE. 
Table 5:  
Solicited Adverse Reactions and Grades 
Reaction 
Grade 1 
Grade 2 
Grade 3 
Grade 41 
Injection site pain 
No interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
Emergency room 
(ER) visit or 
hospitalization 
Injection site erythema 
(redness) 
25 - 50 mm/ 
2.5 - 5 cm 
51 - 100 mm/ 
5.1 - 10 cm 
> 100 mm/ 
> 10 cm 
Necrosis or 
exfoliative dermatitis 

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Reaction 
Grade 1 
Grade 2 
Grade 3 
Grade 41 
Injection site 
swelling/induration 
(hardness) 
25 - 50 mm/ 
2.5 - 5 cm 
51 - 100 mm/ 
5.1 - 10 cm 
> 100 mm/ 
> 10 cm 
Necrosis 
Axillary (underarm) 
swelling or tenderness 
ipsilateral to the side of 
injection* 
No interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
ER visit or 
hospitalization 
Headache 
No interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
ER visit or 
hospitalization 
Fatigue 
No interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
ER visit or 
hospitalization 
Myalgia (muscle aches 
all over body) 
No interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
ER visit or 
hospitalization 
Arthralgia (joint aches 
in several joints) 
No interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
ER visit or 
hospitalization 
Nausea/vomiting 
No interference 
with activity or 
1-2 episodes/ 
24 hours 
Some 
interference 
with activity or 
> 2 episodes/ 
24 hours 
Prevents daily 
activity, requires 
outpatient IV 
hydration 
ER visit or 
hospitalization for 
hypotensive shock 
Chills 
No interference 
with activity 
Some 
interference 
with activity not 
requiring 
medical 
intervention 
Prevents daily 
activity and 
requires medical 
intervention 
ER visit or 
hospitalization 
Fever (oral) 
38.0 – 38.4°C 
100.4 – 101.1°F 
38.5 – 38.9°C 
101.2 – 102.0°F 
39.0 – 40.0°C 
102.1 – 104.0°F 
> 40.0°C 
> 104.0°F 
Abbreviation: ER = Emergency room. 
Note: Events listed above but starting > 7 days post study injection will be recorded on the AE page of the eCRF. 
Causality for each event reported on the AE page will be determined per assessment by the Investigator. 
1 Grading of Grade 4 events will be determined per Investigator and assessment is recorded on the reactogenicity 
event page in the electronic case report form. 
Source: Guidance for Industry – Toxicity Grading Scale for Heathy Adult and Adolescent Volunteers Enrolled in 
Preventive Vaccine Clinical Trials (DHHS 2007). 

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8.10.4. 
Medically Attended Adverse Events 
An MAAE is an AE that leads to an unscheduled visit to an HCP. This would include visits to a 
study clinic for unscheduled assessments (eg, rash assessment, abnormal laboratory follow-up) 
and visits to HCPs external to the study clinic (eg, emergency room, urgent care, primary care 
physician). Investigators will review unsolicited AEs for the occurrence of any MAAEs. 
Unsolicited AEs will be captured on the AE page of the eCRF. 
An unscheduled visit for assessment of protocol-defined ILI (symptoms assessment and NP 
swab) is not considered an MAAE unless additional medical evaluation, including 
examinations/testing not required per protocol, and/or treatment is provided during the visit, OR 
if the participant meets RT-PCR confirmed influenza infection (RT-PCR with positive result for 
influenza) (Section 8.10.5). 
8.10.5. 
Influenza-like Illness Case Definitions 
Protocol-defined ILI: 
A protocol-defined ILI is defined as body temperature ≥ 37.5°C [≥ 99.5°F]) accompanied by at 
least 1 respiratory illness symptom (sore throat, cough, sputum production, wheezing, or 
difficulty breathing).  
CDC-defined ILI: 
A CDC-defined ILI is defined as body temperature ≥ 37.8°C (≥ 100°F) accompanied by cough 
and/or sore throat. 
RT-PCR-confirmed Influenza Infection: 
An RT-PCR-confirmed influenza infection is defined as a positive influenza result on a 
respiratory sample by RT-PCR within 7 days of onset of protocol- or CDC-defined ILI 
performed at any setting during the study period. 
Culture-confirmed Influenza Infection: 
Culture-defined ILI is defined as a positive influenza result by viral culture following a positive 
influenza result by RT-PCR. Viral cultures will only be done on samples with a positive 
influenza result by RT-PCR. 
Similarity to Strains Selected for the Seasonal Vaccine: 
A laboratory-confirmed isolate is deemed similar to one of the vaccine components if determined 
by antigenic testing of the cultured virus using specific antisera and/or by genetic sequencing of 
the HA segments showing identity of key antigenic residues with vaccine strain-like strains. 
Antigenic Matched to Strains Selected for the Seasonal Vaccine 
Culture-confirmed viruses are deemed to be antigenically similar to vaccine strains by antigenic 
testing of the cultured virus using specific antisera. 
8.10.6. 
Adverse Events of Special Interest 
An AESI is an AE (serious or nonserious) of scientific and medical concern specific to the 
Sponsor’s product or program, for which ongoing monitoring and immediate notification by the 

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Investigator to the Sponsor are required. Such events may require further investigation to 
characterize and understand them. 
AESIs for this protocol are described in Section 11.4. 
All AESIs will be collected through the entire study period and must be reported to the Sponsor 
or designee immediately and in all circumstances within 24 hours of becoming aware of the 
event via the electronic data capture system. If a site received a report of a new AESI from a 
participant or receives updated information on a previously reported AESI at a time after the 
eCRF has been taken offline, then the site should report this information on the paper SAE/AESI 
Report Form provided to the study site via email or fax as provided on the form (Section 8.9.8). 
8.10.6.1. Anaphylaxis 
All suspected (ie, related to study intervention) cases of anaphylaxis should be recorded as 
MAAEs and AESIs and reported as an SAE, based on the criteria for a medically important 
event, unless the event meets other serious criteria. As an SAE, the event should be reported to 
the Sponsor or designee immediately and in all circumstances within 24 hours, per Section 8.9.8. 
The Investigator will submit any updated anaphylaxis case data to the Sponsor within 24 hours 
of it being available. For reporting purposes, a participant who displays signs or symptoms 
consistent with anaphylaxis (as below) should be reported as a potential case of anaphylaxis. 
This is provided as general guidance for Investigators and is based on the Brighton Collaboration 
case definition (Rüggeberg et al 2007). 
Anaphylaxis is an acute hypersensitive reaction with multi-organ system involvement that can 
present as, or rapidly progress to, a severe life-threatening reaction. It may occur following 
exposure to allergens from a variety of sources. 
Anaphylaxis is a clinical syndrome characterized by the following: 
• Sudden onset AND 
• Rapid progression of signs and symptoms AND 
• Involves 2 or more organ systems, as follows: 
− Skin/mucosal: urticaria (hives), generalized erythema, angioedema, generalized pruritus 
with skin rash, generalized prickle sensation, red and itchy eyes. 
− Cardiovascular: measured hypotension, clinical diagnosis of uncompensated shock, loss 
of consciousness or decreased level of consciousness, evidence of reduced peripheral 
circulation. 
− Respiratory: bilateral wheeze (bronchospasm), difficulty breathing, stridor, upper 
airway swelling (lip, tongue, throat, uvula, or larynx), respiratory distress, persistent dry 
cough, hoarse voice, sensation of throat closure, sneezing, rhinorrhea. 
− Gastrointestinal: diarrhea, abdominal pain, nausea, vomiting. 

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8.10.6.2. Myocarditis/Pericarditis 
A case of suspected, probable, or confirmed myocarditis, pericarditis, or myopericarditis should 
be reported as an AESI, even if it does not meet criteria per the CDC Working Case Definitions. 
The event should also be reported as an SAE if it meets seriousness criteria (see Section 8.9.8). 
An independent Cardiac Event Adjudication Committee (CEAC) will review suspected cases of 
myocarditis, pericarditis, and myopericarditis to determine if they meet CDC criteria for 
“probable” or “confirmed” events (Section 8.11.2). 
The CDC Working Case Definitions are provided in Section 11.5 as guidance. 
8.10.7. 
Assessment of Intensity/Severity 
An event is defined as “serious” when it meets at least one of the predefined outcomes as 
described in the definition of an SAE (Section 8.9.8), NOT when it is rated as severe.  
The severity (or intensity) of an AR or AE refers to the extent to which it affects the participant’s 
daily activities. The Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers 
Enrolled in Preventative Vaccine Clinical Trials (DHHS 2007) will be used to categorize local 
and systemic reactogenicity events (solicited ARs), clinical laboratory test results, and vital sign 
measurements observed during this study. Specific criteria for local and systemic reactogenicity 
events are presented in Section 8.10.3.  
The determination of severity for all unsolicited AEs should be made by the Investigator based 
upon medical judgment and the definitions of severity as follows:  
• Mild: These events do not interfere with the participant’s daily activities.  
• Moderate: These events cause some interference with the participant’s daily activities and 
require limited or no medical intervention.  
• Severe: These events prevent the participant’s daily activity and require intensive 
therapeutic intervention.  
Study staff should elicit from the participant the impact of AEs on the participant’s activities of 
daily living to assess severity and document appropriately in the participant’s source 
documentation. An AE characterized as intermittent requires documentation of onset and 
duration of each episode. An AE that fluctuates in severity during the course of the event is 
reported once in the eCRF at the highest severity observed. 
8.10.8. 
Assessment of Causality 
The Investigator will assess causality (ie, whether there is a reasonable possibility that the study 
intervention caused the event) for all AEs and SAEs. The relationship will be characterized using 
the following classification:  
Not related: There is not a reasonable possibility of a relationship to the study intervention. 
Participant did not receive the study intervention OR temporal sequence of the AE onset relative 
to administration of the study intervention is not reasonable OR the AE is more likely explained 
by another cause than the study intervention.  

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Related: There is a reasonable possibility of a relationship to the study intervention. There is 
evidence of exposure to the study intervention. The temporal sequence of the AE onset relative 
to the administration of the study intervention is reasonable. The AE is more likely explained by 
the study intervention than by another cause. 
8.11. 
Safety Oversight 
8.11.1. 
Data and Safety Monitoring Board 
A DSMB will be used throughout the conduct of this study. This committee will be composed of 
independent members with relevant therapeutic and/or biostatistical expertise to allow for the 
ongoing review of safety data from this study population. Safety data will be reviewed according 
to intervals defined in the DSMB charter and will also occur as needed. 
8.11.2. 
Independent Cardiac Event Adjudication Committee 
An independent Cardiac Event Adjudication Committee (CEAC) of medically qualified 
personnel, including cardiologists, will review suspected cases of myocarditis and pericarditis to 
determine if they meet CDC criteria of “probable” or “confirmed” events, and to assess severity 
(Gargano et al 2021). Any cases that the CEAC assesses as representing probable or confirmed 
cases of myocarditis or pericarditis will be referred to the Sponsor, who will then make a final 
decision on whether to suspend further enrollment and/or study dosing based on an assessment of 
the overall potential risk to study participants. 
The CEAC will operate under the rules of an approved charter that will be written and reviewed 
at the organizational meeting of the CEAC. Details regarding the CEAC composition, 
responsibilities, procedures, and frequency of data review will be defined in its charter. 
8.12. 
Treatment of Overdose 
As the study intervention is to be administered by a HCP, it is unlikely that an overdose will 
occur. 
However, in the event of an overdose, the Investigator should: 
1. Contact the Medical Monitor immediately. 
2. Closely monitor the participant for any AE/SAE and laboratory abnormalities until the 
last safety follow-up visit. 
3. Report any signs or symptoms associated with the overdose as an AE and record details 
in the relevant AE/SAE sections in the eCRF. 
4. Document the quantity of the excess dose in the eCRF. 
8.13. 
Pharmacokinetics 
Pharmacokinetic parameters are not evaluated in this study. 
8.14. 
Pharmacodynamics  
Pharmacodynamic parameters are not evaluated in this study.  

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8.15. 
Biomarkers 
Additional biomarkers may be evaluated as part of future research objectives and development. 
Biomarker assessments may be evaluated as part of the study, which may include serum 
antibody levels, genomic and transcriptomics studies from consented participants.  
According to the ICF (Section 11.1.6), serum from biomarker testing may be used for future 
research, which may be performed at the discretion of the Sponsor to further characterize the 
immune response to influenza vaccines, additional assay development, and the immune response 
across influenza viruses (Section 11.1.10). Optional blood collections for DNA and mRNA 
sequencing may be performed to research connections between vaccine responses and safety. 
NP swabs collected in the study may be used for assay development purposes.  
8.16. 
Patient-Reported Outcomes and Medical Resource Utilization 
Exploratory objectives related to patient-reported outcomes (PROs) and medical resource 
utilization are listed in Section 3. 
Patient-reported outcomes and medical resource utilization associated with symptoms of ILI will 
be assessed at time points specified in the SoE (Table 1). 
8.16.1. 
Patient-reported Outcome Measures 
Patient-reported outcome measures will include the following questionnaires: EFS, EQ-5D-5L 
scale, and WPAI:ILI. 
8.16.1.1. EFS 
At Day 1, the EFS will be collected by clinical staff for participants aged 65 years and older. 
This scale is a brief, valid, and reliable tool for assessment of frailty across 9 domains: cognition, 
general health status, functional independence, social support, medication use, nutrition, mood, 
continence, and functional performance. 
8.16.1.2. EQ-5D-5L 
The EQ-5D-5L consists of both the EQ-5D descriptive system and the EQ visual analogue scale. 
For all participants, responses to the EQ-5D-5L will be collected using the eDiary at Day 1 
(baseline), Day 91, Day 181, Day 271, and Day 361 (Month 12)/EoS. For participants reporting 
symptoms of ILI, the EQ-5D-5L responses will be collected using the eDiary on the day of 
symptoms reporting (+1 day), and 5 days (+1 day) later. 
8.16.1.3. WPAI 
For participants reporting symptoms of ILI, the WPAI over the previous 7 days will be collected 
using the eDiary at 5 days (+1 day) following start of the symptoms. The participant will be 
prompted to report productivity or activity impairment related to their ILI. The list of the ILI 
symptoms that are part of their reporting of symptoms are the specific health problem to be 
considered. 

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8.16.2. 
Medical Resource Utilization 
8.16.2.1. Hospitalization 
For hospital stay (new hospitalization or prolongation of existing hospital stay), the following 
information will be collected for confirmed influenza cases from SAE and MAAE reports: 
• Admission date 
• Discharge date 
• Intensive care unit stay (yes or no) 
8.16.2.2. Outpatient Medical Resource Utilization 
For participants reporting MAAEs, outpatient medical resource utilization will be collected, 
where available. Options that will be provided are: outpatient/physician visit; emergency 
room/urgent care visit; and telemedicine visit. 

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9. 
STATISTICAL CONSIDERATIONS 
9.1. 
Blinding and Responsibility for Analyses 
This is an observer-blind study. The Investigator, clinic staff, study participants, site monitors, 
and Sponsor personnel (or its designees) will be blinded to the study intervention administered 
until the study database is locked and unblinded, with the following exceptions: 
• Unblinded personnel (of limited number) will be assigned to vaccine accountability 
procedures and will prepare the study intervention for all participants. These personnel 
will have no study functions other than the study intervention management, 
documentation, accountability, preparation, and administration. They will not be involved 
in participant evaluations and will not reveal the identity of the study intervention to 
either the participant or the blinded clinic personnel involved in the conduct of the study 
unless this information is necessary in the case of an emergency. 
• Unblinded clinic personnel will administer the study intervention. They will not be 
involved in assessments of any study endpoints. 
• Unblinded site monitors, not involved in other aspects of monitoring, will be assigned as 
the study intervention accountability monitors. They will have responsibilities to ensure 
that sites are following all proper study intervention accountability, preparation, and 
administration procedures. 
• An independent unblinded statistical and programming team will perform the preplanned 
interim analyses (Section 9.5.4). Sponsor team members will be pre-specified to be 
unblinded to the interim analyses results and will not communicate the results to the 
blinded Investigators, clinic staff, clinical monitors, or participants. 
• The DSMB may review data, as appropriate, to safeguard the interests of clinical trial 
participants and to help ensure the integrity of the study. 
The dosing assignment will be concealed by having the unblinded pharmacy personnel prepare 
the study intervention in a secure location that is not accessible or visible to other clinic staff. An 
opaque sleeve over the syringe used for injection will maintain the blind at the time of injection, 
as mRNA-1010 will look different from the active comparator. Only delegated unblinded clinic 
staff will conduct the injection procedure. Once the injection is completed, only the blinded 
clinic staff will perform further assessments and interact with the participants. Access to the 
randomization code will be strictly controlled at the pharmacy. 
Procedures for breaking the blind in the case of a medical emergency are provided in 
Section 6.3.7. 
9.2. 
Statistical Hypotheses 
The primary efficacy objective of this study is to evaluate relative vaccine efficacy (rVE) of 
mRNA-1010 as compared to an active comparator, to prevent the occurrence of the first episode 
of RT-PCR confirmed protocol-defined ILI caused by any influenza A or B virus strains. 
The null hypothesis to be tested first is that the rVE of mRNA-1010 as compared to an active 
comparator is inferior, using a 10% noninferiority margin (NIM), (ie, H01: rVE≤ -10%). The rVE 

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is defined as the percent of reduction in the hazards of the primary endpoint (mRNA-1010 vs. 
active comparator). Equivalently, the null hypothesis is: H01: hazard ratio (HR) ≥ 1.1  
A stratified Cox proportional hazard model will be used to assess the HR between mRNA-1010 
and the active comparator at a 1-sided 2.5% significance level, using the PP Set. 
The trial will be considered to meet the primary efficacy objective by demonstrating 
noninferiority (NI) of mRNA-1010 to the active comparator if the p-value for rejecting HR ≥ 1.1 
is less than the nominal p-value based on the Lan-DeMets Pocock approximation spending 
function at the IA or final analysis, on the PP Set. Cases will be counted starting 14 days after the 
vaccination. 
Once NI is demonstrated, the rVE will be further evaluated using the same endpoint for 
superiority. The null hypothesis to be tested is H02: rVE ≤ 0%. Equivalently, the null hypothesis 
is: H02: HR ≥ 1. 
Superiority of mRNA-1010 versus (vs.) the active comparator on the primary efficacy endpoint 
will be concluded if the p-value for rejecting HR ≥ 1 is less than the nominal p-value based on 
the Lan-DeMets Pocock approximation spending function, on the mITT Set. 
9.3. 
Sample Size  
The sample size is driven by the total number of cases to demonstrate rVE (mRNA-1010 vs. 
active comparator) to prevent the first episode of RT-PCR confirmed protocol-defined ILI 
caused by any influenza A or B virus strains. 
Under the assumption of proportional hazards and with 1:1 randomization of mRNA-1010 and 
active comparator, a total of 365 cases on the PP Set will provide at least 93% power to establish 
a NI claim with a selected NIM = 10%, ie, rejecting the null hypothesis H01: rVE ≤ -10%, with 
one IA using the Lan-DeMets Pocock boundary for efficacy and a log-rank test statistic with an 
overall 1-sided Type I error rate of 2.5%. 
The number of cases will be continuously monitored using external epidemiologic data (eg, 
CDC.gov). It is projected that by middle of February 2023, approximately 274 cases (75% of the 
targeted cases) will be observed in the PP Set. In the scenario that fewer cases are observed by 
middle of February, the IA will still be conducted around this timeframe because of the 
seasonality of influenza in the Northern Hemisphere, and the nominal alpha to be spent that the 
IA and final analysis will be adjusted accordingly.  
The total number of cases pertains to the PP Set accruing at least 14 days after study 
intervention.  
Approximately 23,000 participants will be randomized with the following assumptions: 
• The target rVE of mRNA-1010 to the active comparator is 25% to prevent the first 
episode of RT-PCR confirmed protocol-defined ILI caused by any influenza A or B virus 
strains. 
• An attack rate of 2% in the active comparator for the primary endpoint. 
• One IA in the middle of February 2023 with approximately 75% of total target cases 
expected across 2 study intervention groups in the PP Set. 

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• A dropout rate ~ 10% (not evaluable for the PP Set). 
• Type I error rate will be adjusted using the Lan-DeMets Pocock boundary. 
If the IA is conducted exactly at 75% of total target cases, the nominal 1-sided Type I error rate 
will be 2.07% at IA and 1.2% at final analysis for NI testing, respectively.  
Once NI is demonstrated, the rVE will be further evaluated for superiority of mRNA-1010 over 
the active comparator. The planned sample size (23,000 participants) is expected to generate 
approximately 386 cases in the mITT Set and will provide approximately 76% power to support 
the superiority claim with the following assumptions: 
• The target rVE of mRNA-1010 to the active comparator is 25% to prevent the first 
episode of RT-PCR confirmed protocol-defined ILI caused by any influenza A or B virus 
strains. 
• An attack rate of 2% in the active comparator for the primary endpoint. 
• An IA in the middle of February 2023 with approximately 290 cases expected (75% of 
total target cases) across 2 study intervention groups in the mITT Set (defined in 
Section 9.4). 
• A dropout rate ~ 4% (not evaluable for the mITT Set). 
• Type I error rate will be adjusted using the Lan-DeMets Pocock boundary. 
The total number of cases pertains to the mITT Set accruing at least 14 days after the study 
intervention. If the IA is conducted exactly at 75% of total target cases, the nominal 1-sided 
Type I error rate will be 2.07% at IA and 1.2% at final analysis, respectively. 
The sample size and power calculations are based on the log-rank test for a survival endpoint 
using the EAST software (version 6.5.2). 
9.4. 
Analyses Populations 
Table 6: 
Populations for Analyses 
Analysis Sets 
Description 
Randomization Set 
All participants who are randomized, regardless of the participants’ 
treatment status in the study. 
Full Analysis Set (FAS) 
All randomized participants who received any study intervention. 
Participants will be analyzed according to the group to which they were 
randomized. 
Modified Intent-to-Treat 
Set (mITT) 
All participants in the FAS except those who discontinued from the study 
prior to 14 days following administration of study intervention.  
The mITT Set will be used as the primary analysis set for efficacy 
endpoints evaluating superiority. 
Participants will be analyzed according to the group to which they were 
randomized. 
Per-Protocol (PP) Set 
All participants in the mITT, excluding those with significant protocol 
deviations that could adversely impact efficacy (eg, disease or 

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Analysis Sets 
Description 
therapeutic intervention that might cause suboptimal response to the 
study intervention). The PP Set will be used as the primary analysis set 
for efficacy endpoints evaluating noninferiority. 
Participants will be analyzed according to the group to which they were 
randomized. 
Immunogenicity Subset 
All participants in the biomarker subset who are in the FAS and have 
baseline and Day 29 antibody assessment via HAI assay. 
Participants will be analyzed according to the group to which they were 
randomized. 
PP Immunogenicity Subset 
The PP Immunogenicity Subset includes all participants in the 
Immunogenicity Subset who received the planned dose of IP, complied 
with the immunogenicity testing schedule, and had no major protocol 
deviations that impact the immunogenicity assessment. Participants with 
RT-PCR–confirmed influenza between Days 1 to 29 will be removed 
from the PP Immunogenicity Set. 
The PP Immunogenicity Set will be used for all analyses of 
immunogenicity unless specified otherwise. 
Participants will be analyzed according to the group to which they were 
randomized. 
Solicited Safety Set 
The Solicited Safety Set consists of all randomized participants who 
received any study intervention and contributed to any solicited adverse 
reaction (AR) data. 
The Solicited Safety Set will be used for the analyses of solicited ARs 
and participants will be included in the vaccination group corresponding 
to the study intervention that they actually received.  
Safety Set 
All randomized participants who received any study intervention. The 
Safety Set will be used for all analyses of safety except for the solicited 
ARs, and participants will be included in the vaccination group 
corresponding to the study intervention that they actually received. 
9.5. 
Statistical Analyses 
This section is a summary of the planned statistical analyses of the primary and secondary 
endpoints.  
The overall Type I error rate for the primary endpoint at the IAs and the final analysis is strictly 
controlled at 2.5% (1-sided) based on the Lan-DeMets Pocock spending function (see 
Section 9.6 for details). The primary efficacy results that will be considered statistically 
significant after consideration of the strategy for controlling the Type I error is described in 
Section 9.5.1. Statistical significance of the primary efficacy endpoint for the primary objective 
can be achieved at either IA or at the final analysis.  
A sequential/hierarchical testing procedure will be used to control Type I error rate over the 
primary efficacy objective (endpoint) and secondary efficacy objectives (endpoints). Secondary 

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efficacy objectives (endpoints) will only be tested at the planned IA or final analysis, whichever 
is applicable, when the primary efficacy endpoint for the primary objective achieves statistical 
significance. In that case, refer Section 9.6.2 for the multiplicity adjustments among the efficacy 
objectives (endpoints). 
9.5.1. 
Efficacy Analyses 
Efficacy analyses will be performed using the FAS, mITT Set, and PP Set, and participants will 
be included in the study intervention group to which they are randomized.  
9.5.1.1. 
Analysis of Primary Efficacy Endpoint 
To assess the efficacy endpoint for the primary objective, preventing the first occurrence of RT-
PCR confirmed protocol-defined ILI within the period of 14 days post study intervention through 
the end of the influenza season, Cox proportional hazards regression model will be used to 
estimate HR. The rVE, ie, 1-HR (mRNA-1010 vs. active comparator) will be estimated along 
with the 2-sided 95% CI and 1-sided p-value for testing H01: rVE ≤ -10%. 
The rVE is defined as the percent reduction in the hazard of the primary endpoint (mRNA-1010 
vs. active comparator) and will be estimated using 1-HR estimand. A stratified Cox proportional 
hazard model with study intervention group as a fixed effect will be used based on the PP Set to 
estimate the HR (mRNA-1010 vs. active comparator). The stratification factors at randomization, 
ie, age group (≥ 50 to < 65 years or ≥ 65 years) and influenza vaccine status in the previous 
season (received or not received), will be applied as the strata variables. The Efron's method will 
be used to handle ties. 
For the primary efficacy endpoint, participants without RT-PCR confirmed protocol-defined ILI 
will be censored at the last study assessment date. Potential intercurrent events may include: 
1. Early discontinuation or death unrelated to influenza; or 
2. Early ILI up to 14 days after study intervention. 
In the estimand of the primary analysis on the primary endpoint, a hypothetical strategy will be 
used to address the intercurrent events in the primary analysis based on the PP Set. The details 
are presented in Section 11.3. 
Participants without RT-PCR confirmed protocol-defined ILI will be censored at Day 181 
(Month 6) or end of influenza season (whichever occurs later), or at the date of early 
discontinuation or death unrelated to influenza, whichever is earlier. Participants with early RT-
PCR confirmed protocol-defined ILI up to 14 days after the study vaccination will be censored at 
the start date of the early RT-PCR confirmed protocol-defined ILI (see Section 11.6 for country-
specific amendment affecting this paragraph. 
The trial will be considered to meet the primary efficacy objective if the p-value for rejecting 
H01: rVE ≤ -10% is less than the nominal p-value based on the Lan-DeMets Pocock boundaries, 
on the PP Set. The nominal alpha at the IA and final analysis will be 2.07% at IA and 1.2% at 
final analysis. 
Analyses of the primary endpoint will be also performed based on the mITT Set using the same 
methods as described above.  

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To support the primary analysis, rVE will also be estimated by 1 minus the ratio of incidence 
rates adjusting for person-time, and the 95% CI of rVE will be computed using the exact method, 
conditional upon the total number of cases adjusting for person-time. 
In addition, Kaplan Meier curve will be used to plot the estimated cumulative incidence rates 
over time by vaccine group. Participants without a case for the primary endpoint identified will 
be censored at Day 181/Month 6 or end of influenza season, whichever ends later. 
Once the noninferiority of mRNA-1010 vs. active comparator is demonstrated using the PP Set, 
superiority of mRNA-1010 vs. active comparator will be evaluated using the same endpoint on 
the mITT Set, either at an IA or at the final analysis. 
9.5.1.2. 
Analysis of Secondary Efficacy Endpoints 
Secondary efficacy endpoints that are defined in Section 3 will be analyzed in a similar way as 
for the primary efficacy endpoint. More details can be found in the SAP. 
9.5.2. 
Safety Analyses 
All safety analyses will be based on the Safety Set, except summaries of solicited ARs, which 
will be based on the Solicited Safety Set. All safety analyses will be provided by vaccination 
group. 
9.5.2.1. 
Adverse Events 
Safety and reactogenicity will be assessed by clinical review of all relevant parameters, including 
solicited ARs (local and systemic events), unsolicited AEs, SAEs, MAAEs, AESIs, AEs leading 
to discontinuation, vital signs, and physical examination findings. 
Unsolicited AEs will be coded by system organ class and preferred term according to the 
MedDRA terminology. The Toxicity Grading Scale for Healthy Adult and Adolescent 
Volunteers Enrolled in Preventive Vaccine Clinical Trials (DHHS 2007) will be used in this 
study. 
The number and percentage of participants with any solicited local AR, solicited systemic AR, 
and any solicited AR during the 7-day follow-up period after the study intervention will be 
summarized. A 2-sided 95% exact CI using the Clopper-Pearson method will also be provided 
for the percentage of participants with any solicited AR for each vaccination group. 
Number and percentage of participants with unsolicited AEs, SAEs, MAAEs, AESIs, severe 
AEs, and AEs leading to discontinuation from the study will be summarized. Numbers of events 
of unsolicited AEs, SAEs, MAAEs, and AESIs will be reported in summary tables accordingly. 
For all other safety parameters, descriptive summary statistics will be provided, and Table 7 
summarizes analysis strategy for safety parameters. Further details will be described in the SAP. 

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Table 7: 
Analysis Strategy for Safety Parameters 
Safety Endpoint 
Number and Percentage of 
Participants,  
Number of Events 
95% CI 
Any Solicited AR (overall and by local, 
systemic) 
X 
X 
Any Unsolicited AE 
X 
 
Any SAE 
X 
 
Any AESI 
X 
 
Any Unsolicited MAAE 
X 
 
Any Unsolicited Treatment-Related AE 
X 
 
Any Treatment-Related SAE 
X 
 
Discontinuation due to AE 
X 
 
Any Grade 3 and above AE 
X 
 
Any Treatment-Related Grade 3 and above AE 
X 
 
Abbreviations: AE = adverse event; AESI = adverse event of special interest; AR = adverse reaction; 
CI = confidence interval; MAAE = medically-attended adverse event; MedDRA = Medical Dictionary for 
Regulatory Activities; SAE = serious adverse event. 
Notes: 95% CI using the Clopper-Pearson method, X = results will be provided. Unsolicited AEs will be 
summarized by system organ class and preferred term coded by MedDRA. 
9.5.2.2. 
Baseline Descriptive Statistics 
Demographic variables (eg, age, sex, race, and ethnicity) and baseline characteristics (eg, height, 
weight, and body mass index) will be summarized by study intervention group in descriptive 
statistics (mean, standard deviation for continuous variable, and number and percentage for 
categorical variables). 
9.5.3. 
Immunogenicity Analyses 
The primary analysis population for immunogenicity will be the PP Immunogenicity Subset, 
unless specified otherwise.  
For each of the 4 strains, the GMT of HAI titers with corresponding 95% CI will be provided at 
each timepoint. The 95% CIs will be calculated based on the t-distribution of the log-transformed 
values then back-transformed to the original scale. The GMFR of HAI titers with corresponding 
95% CI at each postbaseline timepoint over baseline will be provided. Descriptive summary 
statistics including median, minimum, and maximum will also be provided.  
An analysis of covariance model will be carried out. The model will include the log-transformed 
HAI titers at Day 29 as the dependent variable, vaccination group as the fixed variable, 
log-transformed baseline HAI titers as a fixed covariate, and adjusting for the stratification 
factors. The geometric least square mean (GLSM) and its corresponding 95% CI results in 
log-transformed scale estimated from the model will be back-transformed to obtain these 
estimates in the original scale as an estimate of the GMT. GMR, estimated by the ratio of GLSM 
and the corresponding 2-sided 95% CI will be provided to assess the treatment difference. The 

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corresponding 2-sided 95% CI of GMR will be provided to assess the difference in immune 
response between the mRNA-1010 group compared with the active comparator group at Day 29.  
For each strain, seroconversion is defined as either a prevaccination HAI titer < 1:10 and a 
postvaccination titer ≥ 1:40 or a prevaccination HAI titer ≥ 1:10 and a minimum 4-fold rise in 
postvaccination HAI antibody titer. 
The number and percentage of participants with seroconversion due to vaccination will be 
provided with 2-sided 95% CI using the Clopper-Pearson method at Day 29. To compare the 
seroconversion rates between the vaccination groups, the Miettinen-Nurminen’s method will be 
used to calculate the 95% CI for the difference in seroconversion rates. The seroconversion rate 
difference with the corresponding 95% CI at Day 29 will be provided for each strain.  
For summarizations of GMTs, antibody titers reported as below the lower limit of 
quantification (LLOQ) will be replaced by 0.5 × LLOQ. Values that are greater than the upper 
limit of quantification (ULOQ) will be converted to the ULOQ. 
In addition, the number and percentage of participants with an HAI titer ≥ 1:40 postinjection due 
to vaccination will be provided with 2-sided 95% CI using the Clopper-Pearson method. 
The analyses will be repeated using the Immunogenicity Subset as a sensitivity analysis. 
9.5.4. 
Exploratory Analyses 
Exploratory endpoints evaluating the rVE will be assessed by similar analysis methods as used 
for the analysis of the primary efficacy endpoint.  
Analyses of the other exploratory endpoints will be described in the SAP. 
9.5.5. 
Subgroup Analyses 
If sufficient case numbers of the primary and key secondary endpoints in a subgroup (ie, age, 
race, etc.) are available, subgroup analysis may be performed. 
9.6. 
Planned Analyses  
9.6.1. 
Interim Analyses 
There is one planned IA with data cut-off around the middle of February 2023 regardless of 
number of influenza cases accrued for the first null hypothesis to be tested to support the primary 
objective. The intent of the IA is for early detection of reliable evidence that rVE of mRNA-1010 
is noninferior to the active comparator. The Lan-DeMets Pocock boundaries are used for 
calculating efficacy boundaries and to preserve the (1-sided) 2.5% Type I error rate over the IA 
and the final analysis (when the target number of cases have been observed), relative to the 
hypothesis: 
H01: HR ≥ 1.1 (equivalently, rVE ≤ - 10%). 
If NI is demonstrated at an IA, the subsequent final analysis will be considered supportive in 
nature for the NI claim. The DSMB will review the IA results and make recommendations to the 
Sponsor in terms of study results reporting and unblinding based on the boundaries of early 
efficacy as described in this section. 

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Table 8 summarizes the timing, number of cases, and decision guidance at each IA and final 
analysis. 
Table 8: Interim Boundaries Using Lan-DeMets Pocock Spending Function, Calculation 
Based on the PP Set for the Endpoint Supporting the Primary Objective  
Information 
Fraction  
(% of total 
#cases) 
Number of 
Cases 
Nominal 
Alpha (1-
sided) ± 
Efficacy 
Boundary 
Rejecting H0: 
rVE ≤ -10% 
Cumulative Probability 
(Crossing Efficacy 
Boundary if the True 
rVE = 25%) 
IA  
(75% cases 
assumed) 
274 
2.07% 
rVE ≥ 14.0% 
(HR ≤ 0.860) 
87.1% 
Final Analysis 
(100%) 
365 
1.2% 
rVE ≥ 13.2% 
(HR ≤ 0.868) 
93.7% 
Abbreviations: HR = hazard ratio; IA: interim analysis; PP = per-protocol; rVE = relative vaccine efficacy. 
±: actual nominal alpha may be adjusted based on the actual information fraction at individual IA(s). 
The study will be considered positive (rVE has been demonstrate) if the p-value for rejecting HR 
≥ 1.1 is less than 2.07% based on the Lan-DeMets Pocock alpha spending function, provided that 
the IA is conducted exactly at 75% information fraction. The final analysis will be performed 
when approximately 365 cases have been observed in the PP Set. In the case that the early study 
success is not achieved, the study will be considered positive at the final analysis if the 1-sided p-
value for rejecting HR ≤1.1 is less than 1.2%.  
If NI is demonstrated, superiority will be evaluated using the same endpoint based on the mITT 
Set, following the test sequence illustrated in Figure 1. Upon successful demonstration of the NI 
claim at the IA, the second null hypothesis to support the superiority objective of the primary 
efficacy endpoint, (ie, H02: HR ≥ 1 [equivalently, rVE ≤ 0%]), will be tested in the mITT Set. 
The superiority is successful at the IA if the 1-sided P value for rejecting HR ≥ 1 is less than 
2.07% using the Lan-DeMets Pocock alpha spending function. Otherwise, the superiority test 
will be conducted again at the final analysis, given that the NI claim has been successfully 
demonstrated (either at the IA or final analysis). The superiority test is successful at the final 
analysis if the 1-sided P value for rejecting HR ≥ 1 is less than 1.2% based on the Lan-DeMets 
Pocock alpha spending function. 
Approximately 290 cases and 386 cases are expected to be observed at the IA and the final 
analysis, respectively, in the mITT Set. 
9.6.2. 
Multiplicity  
To control the overall Type I error for the study, a hierarchical testing strategy will be used to 
test the primary and secondary efficacy endpoints (Figure 1). 

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Figure 1: 
Testing Sequence of the Primary and Secondary Endpoints 
 
 
Noninferiority of mRNA-1010 vs. the active comparator on the primary efficacy endpoint will be 
declared if the p-value for rejecting HR ≥ 1.1 is less than the nominal p-value based on the Lan-
DeMets Pocock approximation spending function, on the PP Set. The nominal alpha levels (1-
sided) are 2.07% at IA and1.2% at the final analysis, respectively, if the IA is conducted when 
75% of total target cases are accumulated across the 2 groups. 
Once the NI criteria is met for the primary efficacy endpoint, superiority of mRNA-1010 relative 
to the active comparator will be tested on the mITT Set. The superiority of rVE will be 
considered demonstrated if the p-value for rejecting HR ≥ 1 is less than the nominal p-value 
based on the Lan-DeMets Pocock approximation spending function, on the mITT Set. For this 
superiority testing, the nominal 1-sided alpha level will be 2.07% at the planned IA and at 1.2% 

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at final analysis, respectively, if the IA is conducted when 75% of total target cases are 
accumulated across the 2 groups. 
If the above superiority is demonstrated, then the following secondary efficacy endpoints will be 
evaluated for NI and superiority in the order outlined in Figure 1 at the final analysis using 1-
sided 2.5% Type I error rate: 
• rVE of mRNA-1010 vaccine vs the active comparator against the first episode of RT-
PCR confirmed protocol-defined ILI caused by influenza A or B strains with similarity to 
the vaccine strains. 
• rVE of mRNA-1010 vaccine vs the active comparator against the first episode of RT-
PCR–confirmed protocol-defined ILI caused by influenza A or B antigenically matched 
influenza A or B strains. 
The testing sequence can only continue to the next level only if all tests at the higher level 
achieve statistical significance at the 1-sided 2.5% alpha level. If a test at the higher level fails to 
demonstrate statistical significance, then the testing sequence will stop, and all testing thereafter 
will not be conducted. 
Analyses of other remaining secondary efficacy endpoints are not controlled for multiplicity. 

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10. 
REFERENCES 
Aretz HT, Billingham ME, Edwards WD, Factor SM, Fallon JT, Fenoglio JJ Jr, et al. 
Myocarditis. A histopathologic definition and classification. Am J Cardiovasc Pathol. 1987;1:3 
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Centers for Disease Control and Prevention (CDC). Atlanta, GA: CDC seasonal flu vaccine 
effectiveness studies. 2020a Dec 11 [cited 2022 Apr 04]. 
Centers for Disease Control and Prevention (CDC) [internet]. Atlanta, GA: Influenza virus 
testing methods. 2020b Aug 10 [cited 2021 Aug 18]. 
Department of Health and Human Services (DHHS), Food and Drug Administration, Center for 
Biologics Evaluation and Research (US). Guidance for industry: Toxicity grading scale for 
healthy adult and adolescent volunteers enrolled in preventive vaccine clinical trials. 
September 2007 [cited 2021 Aug 19]. Available from: 
https://www.fda.gov/downloads/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInfor
mation/Guidances/Vaccines/ucm091977.pdf. 
Food and Drug Administration. Conduct of clinical trials of medical products during the 
COVID-19 public health emergency: guidance for industry, investigators, and institutional 
review boards. 2020 Mar [updated: 2021 Aug 30; cited: 2021 Oct 04]. Available from: 
https://www.fda.gov/media/136238/download. 
Gargano JW, Wallace M, Hadler SC, Langley G, Su JR, Oster ME, et al. Use of mRNA 
COVID-19 vaccine after reports of myocarditis among vaccine recipients: update from the 
Advisory Committee on Immunization Practices – United States, June 2021. MMWR Morb 
Mortal Wkly Rep. 2021;70(27):977-82. 
ModernaTX, Inc. A Study of mRNA-1010 Seasonal Influenza Vaccine in Healthy Adults. In: 
ClinicalTrials.gov [internet]. Bethesda (MD): National Library of Medicine (US). 2021 Jul 09 
[updated 2021 Jul 15; cited 2021 Sep 13]. Available from: 
https://clinicaltrials.gov/ct2/show/NCT04956575. NLM identifier: NCT04956575. 
Monto AS. Reflections on the Global Influenza Surveillance and Response System (GISRS) at 
65 years: an expanding framework for influenza detection, prevention, and control. Influenza 
Other Respir Viruses. 2018;12(1):10-12. 
Riedel S, Hobden JA, Miller S, Morse SA, Mietzner TA, Detrick B, et al. Orthomyxoviruses 
(Influenza Viruses). In: Riedel S, Morse SA, Mietzner TA, Miller S, eds. Jawetz, Melnick & 
Adelberg’s Medical Microbiology. 28th ed. New York, New York: McGraw-Hill Education; 
2019. p. 565-78. 
Rockman S, Laurie KL, Parkes S, Wheatley A, Barr IG. New technologies for influenza 
vaccines. Microorganisms. 2020;8(11):1745. 
Rüggeberg JU, Gold MS, Bayas JM, Blum MD, Bonhoeffer J, Friedlander S, et al; Brighton 
Collaboration Anaphylaxis Working Group. Anaphylaxis: case definition and guidelines for data 
collection, analysis, and presentation of immunization safety data. Vaccine. 2007;25(31):5675-
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Shimabukuro TT, Cole M, Su JR. Reports of anaphylaxis after receipt of mRNA COVID-19 
vaccines in the US – December 14, 2020-January 18, 2021. JAMA. 2021;325(11):1101-2. 
World Health Organization (WHO). Geneva, Switzerland: Influenza (seasonal): Ask the expert: 
influenza Q&A. 2018 Nov 6 [cited 2022 Apr 04]. Available from: https://www.who.int/news-
room/fact-sheets/detail/influenza-(seasonal). 
Zent O, Arras-Reiter C, Broeker M, Hennig R. Immediate allergic reactions after vaccinations – 
a post-marketing surveillance review. Eur J Pediatr. 2002;161(1):21-5.

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11. 
SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS 
 

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11.1. 
APPENDIX 1: Study Governance Considerations 
11.1.1. 
Regulatory and Ethical Considerations 
This study will be conducted in accordance with the protocol and with the following: 
• Consensus ethical principles derived from international guidelines including the 
Declaration of Helsinki and Council for International Organizations of Medical Sciences 
(CIOMS) International Ethical Guidelines. 
• Applicable ICH Good Clinical Practice (GCP) Guidelines. 
• Applicable laws and regulatory requirements. 
• The protocol, protocol amendments, ICF, IB, and other relevant documents (eg, 
advertisements) must be submitted to an IRB/IEC by the Investigator and reviewed and 
approved by the IRB/IEC before the study is initiated. 
• Any amendments to the protocol will require IRB/IEC approval before implementation of 
changes made to the study design, except for changes necessary to eliminate an 
immediate hazard to study participants. 
• The Investigator will be responsible for the following: 
− Providing written summaries of the status of the study to the IRB/IEC annually or 
more frequently in accordance with the requirements, policies, and procedures 
established by the IRB/IEC 
− Notifying the IRB/IEC of SAEs or other significant safety findings as required by 
IRB/IEC procedures 
− Providing oversight of the conduct of the study at the site and adherence to 
requirements of 21 CFR, ICH guidelines, the IRB/IEC, European regulation 536/2014 
for clinical studies (if applicable), and all other applicable local regulations. 
11.1.2. 
Study Monitoring  
Before an investigational site can enter a participant into the study, a representative of 
ModernaTX, Inc. or its representatives will perform a remote or onsite visit with the 
investigational study clinic to: 
• Determine the adequacy of the facilities. 
• Discuss with the Investigator(s) and other personnel their responsibilities with regard to 
protocol adherence, and the responsibilities of ModernaTX, Inc. or its representatives. 
This will be documented in a Clinical Study Agreement between ModernaTX, Inc., 
designated CRO, and the Investigator. 
According to ICH GCP guideline, the Sponsor of the study is responsible for ensuring the proper 
conduct of the study with regard to protocol adherence and validity of data recorded on the 
eCRFs. The study monitor’s duties are to aid the Investigator and ModernaTX, Inc. in the 
maintenance of complete, accurate, legible, well-organized, and easily retrievable data. The 
study monitor will advise the Investigator of the regulatory necessity for study-related 

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monitoring, audits, IRB/IEC review, and inspection by providing direct access to the source 
data/documents. In addition, the study monitor will explain to and interpret for the Investigator 
all regulations applicable to the clinical evaluation of a study intervention as documented in ICH 
guidelines. 
It is the study monitor’s responsibility to inspect the eCRFs and source documentation 
throughout the study to protect the rights of the participants; to verify adherence to the protocol; 
to verify completeness, accuracy, and consistency of the data; and to confirm adherence of study 
conduct to any local regulations. Details will be outlined in the clinical monitoring plan. During 
the study, a monitor from ModernaTX, Inc. or a representative will have regular contacts with 
the investigational site, for the following: 
• Provide information and support to the Investigator(s). 
• Confirm that facilities remain acceptable. 
• Confirm that the investigational team is adhering to the protocol, that the data are being 
accurately recorded in the eCRFs, and that study intervention accountability checks are 
being performed. 
• Perform source data verification. This includes a comparison of the data in the eCRFs 
with the participant’s medical records at the hospital or practice, and other records 
relevant to the study. This will require direct access to all original records for each 
participant (eg, clinical charts or electronic medical record system). 
• Record and report any protocol deviations not previously sent. 
• Confirm AEs and SAEs have been properly documented on eCRFs and confirm any 
SAEs have been forwarded to the SAE Hotline, and those SAEs that met criteria for 
reporting have been forwarded to the IRB/IEC. 
The monitor will be available between visits if the Investigator(s) or other staff needs 
information or advice. 
11.1.3. 
Audits and Inspections  
ModernaTX, Inc., their designee(s), the IRB/IEC, or regulatory authorities will be allowed to 
conduct site visits to the investigational facilities for the purpose of monitoring or inspecting any 
aspect of the study. The Investigator agrees to allow ModernaTX, Inc., their designee(s), the 
IRB/IEC, or regulatory authorities to inspect the study intervention storage area, study 
intervention stocks, study intervention records, participant charts and study source documents, 
and other records relative to study conduct.  
Authorized representatives of ModernaTX, Inc., a regulatory authority, and any IRB/IEC may 
visit the site to perform audits or inspections, including source data verification. The purpose of a 
Sponsor audit or inspection is to systematically and independently examine all study-related 
activities and documents to determine whether these activities were conducted, and data were 
recorded, analyzed, and accurately reported according to the protocol, International Council for 
Harmonisation Good Clinical Practice (ICH GCP E6 [R2]), and any applicable regulatory 
requirements. The Investigator should contact ModernaTX, Inc. immediately if contacted by a 
regulatory agency about an inspection. 

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The Principal Investigator must obtain IRB approval for the investigation. Initial IRB approval, 
and all materials approved by the IRB for this study including the participant consent form and 
recruitment materials must be maintained by the Investigator and made available for inspection. 
11.1.4. 
Financial Disclosure 
The Investigator is required to provide financial disclosure information to allow the Sponsor to 
submit the complete and accurate certification or disclosure statements required under 21 CFR 54. 
In addition, the Investigator must provide the Sponsor with a commitment to promptly update 
this information if any relevant changes occur during the course of the investigation and for 
1 year following the completion of the study. 
The Sponsor, the CRO, and the study site are not financially responsible for further testing or 
treatment of any medical condition that may be detected during the screening process. In addition, 
in the absence of specific arrangements, the Sponsor, the CRO, and the study site are not 
financially responsible for further treatment of the disease under study. 
11.1.5. 
Recruitment Strategy 
Enrollment targets will be established to ensure the participant population reflects those that are 
most at risk for the condition, or those that are most reflective of the general population, if 
appropriate. 
Participant recruitment and retention initiatives will be incorporated into the trial. These include, 
but are not limited to, services that provide a means to identify potential participants and direct 
them to participating clinical trial sites, participant support services such as concierge, and trial 
information and support collateral for both the participant and the site. Advertisements to be 
used for the recruitment of study participants, and any other written information regarding 
this study to be provided to the participant should be submitted to the Sponsor for approval. All 
documents must be approved by the IRB/IEC.  
11.1.6. 
Informed Consent Process 
The informed consent document(s) must meets the requirements of 21 CFR 50, local regulations, 
ICH guidelines, Health Insurance Portability and Accountability Act (HIPAA) requirements, 
where applicable, and the IRB/IEC or study center. All consent documents will be approved by 
the appropriate IRB/IEC. The actual ICF used at each center may differ, depending on local 
regulations and IEC/IRB requirements. However, all versions must contain the standard 
information found in the sample ICF provided by the Sponsor. Any change to the content of the 
ICF must be approved by the Sponsor and the IEC/IRB prior to the form being used. 
If new information becomes available that may be relevant to the participant’s willingness to 
continue participation in the study, this will be communicated to the participant in a timely 
manner. Such information will be provided via a revised ICF or an addendum to the original ICF. 
The Investigator or their representative will explain the nature of the study to the participant and 
answer all questions regarding the study. 
The Investigator is responsible for ensuring that the participant fully understands the nature and 
purpose of the study. Information should be given in both oral and written form whenever 
possible.  

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No participant should be obliged to participate in the study. The participant must be informed 
that participation is voluntary. Participants, their relatives, guardians, or (if applicable) legal 
representatives must be given ample opportunity to inquire about details of the study. The 
information must make clear that refusal to participate in the study or withdrawal from the study 
at any stage is without any prejudice to the participant’s subsequent care.  
The participant must be allowed sufficient time to decide whether they wish to participate. 
The participant must be made aware of and give consent to direct access to their source medical 
records by study monitors, auditors, the IRB/IEC, and regulatory authorities. The participant 
should be informed that such access will not violate participant confidentiality or any applicable 
regulations. The participant should also be informed that they are authorizing such access by 
signing the ICF. 
A copy of the ICF(s) must be provided to the participant. 
A participant who is rescreened is not required to sign another ICF if the rescreening occurs 
within 28 days from the previous ICF signature date. 
The ICF will contain a separate section/consent form(s) that addresses the use of remaining 
mandatory samples for optional exploratory research. The Investigator or authorized designee 
will explain to each participant the objectives of the exploratory research. A participant will be 
told that they are free to refuse participation and may withdraw their consent at any time and for 
any reason during the storage period. A separate signature will be required to document 
agreement to allow any remaining specimens to be used for exploratory research. A participant 
who decline to participate in this optional research will not provide this separate signature. 
11.1.7. 
Protocol Amendments 
No change or amendment to this protocol may be made by the Investigator or the Sponsor after 
the protocol has been agreed to and signed by all parties unless such change(s) or amendment(s) 
has (have) been agreed upon by the Investigator or the Sponsor. Any change agreed upon will be 
recorded in writing, and the written amendment will be signed by the Investigator and the 
Sponsor. Institutional review board approval is required prior to the implementation of an 
amendment, unless overriding safety reasons warrant immediate action, in which case the 
IRB(s)/IEC(s) will be promptly notified. 
Any modifications to the protocol or the ICF, which may impact the conduct of the study, 
potential benefit of the study, or may affect participant safety, including changes of study 
objectives, study design, participant population, sample sizes, study procedures, or significant 
administrative aspects will require a formal amendment to the protocol. Such amendment will be 
released by the Sponsor, agreed by the Investigator(s), and approved by the relevant 
IRB(s)/IEC(s) prior to implementation. A signed and dated statement that the protocol, any 
subsequent relevant amended documents and the ICF have been approved by relevant 
IRB(s)/IEC(s) must to be provided to the Sponsor before the study is initiated. 
Administrative changes of the protocol are minor corrections and/or clarifications that have no 
effect on the way the study is to be conducted. These administrative changes will be released by 
the Sponsor, agreed by the Investigator(s), and notified to the IRB(s)/IEC(s). 

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11.1.8. 
Protocol Deviations  
The noncompliance may be either on the part of the participant, the Investigator, or the study site 
staff. As a result of deviations, corrective actions are to be developed by the site and 
implemented promptly. 
It is the responsibility of the site Investigator to use continuous vigilance to identify and report 
deviations within in a timely manner of the scheduled protocol-required activity. All deviations 
must be addressed in study source documents and reported to the Sponsor and the study medical 
monitor. Protocol deviations must be sent to the reviewing IRB/IEC per their policies. The site 
Investigator is responsible for knowing and adhering to the reviewing IRB/IEC requirements. 
11.1.9. 
Data Protection 
Participants will be assigned a unique identifier by the Sponsor. Any participant records or 
datasets that are transferred to the Sponsor will contain the identifier only; participant names or 
any information which would make the participant identifiable will not be transferred. 
The participant must be informed that their personal study-related data will be used by the 
Sponsor in accordance with local data protection law. The level of disclosure must also be 
explained to the participant. 
The participant must be informed that their medical records may be examined by Clinical 
Quality Assurance auditors or other authorized personnel appointed by the Sponsor, by 
appropriate IRB/IEC members, and by inspectors from regulatory authorities. 
Individual participant medical information obtained as a result of this study is considered 
confidential, and disclosure to third parties is prohibited. Information will be accessible to 
authorized parties or personnel only. Medical information may be given to the participant’s 
physician or to other appropriate medical personnel responsible for the participant’s well-being. 
Each participant will be asked to complete a form allowing the Investigator to notify the 
participant’s primary health care provider of their participation in this study.  
All laboratory specimens, evaluation forms, reports, and other records will be identified in a 
manner designed to maintain participant confidentiality. All records will be kept in a secure 
storage area with limited access. Clinical information will not be released without the written 
permission of the participant except as necessary for monitoring and auditing by the Sponsor, 
its designee, relevant regulatory authority, or the IRB. 
The Investigator and all employees and coworkers involved with this study may not disclose or 
use for any purpose other than performance of the study, any data, record, or other unpublished, 
confidential information disclosed to those individuals for the purpose of the study. Prior written 
agreement from the Sponsor or its designee must be obtained for the disclosure of any 
confidential information to other parties. 
• The contract between the sponsor or designee and the study sites may specify 
responsibilities of the parties related to data protection, including handling of data 
security breaches and respective communication and cooperation of the parties. 
• Information technology systems used to collect, process, and store study-related data are 
secured by technical and organizational security measures designed to protect such data 
against accidental or unlawful loss, alteration, or unauthorized disclosure or access. 

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11.1.10. 
Sample Retention and Future Biomedical Research 
Samples may be used for purposes related to this research. The Sponsor may store samples for 
the time frame specified in the ICF to achieve study objectives. In addition, identifiable samples 
can be destroyed at any time at the request of the participant. 
These samples could be used to address further scientific questions related to mRNA-1010 or 
anti respiratory virus immune response, to research the complications associated with influenza 
and other conditions for which individuals with influenza are at increased risk, and to improve 
treatment. During the study or during the retention period, in addition to the analysis outlined in 
the study endpoints, exploratory analysis may be conducted using other measures of adaptive 
immunity to seasonal influenza to include humoral and cellular immune assay methodologies on 
any remaining blood or serum samples, including samples from participants who are screened 
but are not subsequently enrolled. A decision to perform such exploratory research may arise 
from new scientific findings related to the drug/vaccine class or disease, as well as reagent and 
assay availability. 
11.1.11. 
Data and Safety Monitoring Board 
A DSMB will be used throughout the conduct of this study. The DSMB will be composed of 
independent members with relevant therapeutic and/or biostatistical expertise to allow for the 
ongoing review of safety data from this study population. The data to be reviewed will be 
unblinded. Safety data will be reviewed according to intervals defined in the DSMB charter and 
as needed if potential safety concerns are identified. 
11.1.12. 
Dissemination of Clinical Study Data 
ModernaTX, Inc. shares information about clinical trials and results on publicly accessible 
websites, based on international and local legal and regulatory requirements, and other clinical 
trial disclosure commitments established by pharmaceutical industry associations. These 
websites include clinicaltrials.gov, EU clinicaltrialregister (eu.ctr), etc., as well as some national 
registries. 
11.1.13. 
Data Quality Assurance and Quality Control 
Data collection is the responsibility of the clinical study staff at the site under the supervision of 
the site Investigator. The Investigator is responsible for ensuring the accuracy, completeness, 
legibility, and timeliness of the data reported. 
• All participant data relating to the study will be recorded on the electronic CRF (eCRF) 
unless transmitted to the Sponsor or designee electronically (eg, laboratory data). The 
Investigator is responsible for verifying that data entries are accurate and correct by 
physically or electronically signing the eCRF. 
• The Investigator must maintain accurate documentation (source data) that supports the 
information entered in the eCRF. 
• The Investigator must permit study-related monitoring, audits, IRB/IEC review, and 
regulatory agency inspections and provide direct access to source data documents. 

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• Monitoring details describing strategy (eg, risk-based initiatives in operations and quality 
such as Risk Management and Mitigation Strategies and Analytical Risk-Based 
Monitoring), methods, responsibilities and requirements, including handling of 
noncompliance issues and monitoring techniques (central, remote, or on-site monitoring) 
are provided in the Clinical Monitoring Plan. 
• The Sponsor or designee is responsible for the data management of this study including 
quality checking of the data. 
• The Sponsor assumes accountability for actions delegated to other individuals (eg, 
Contract Research Organizations). 
• Study monitors will perform ongoing source data verification to confirm that data entered 
into the CRF by authorized site personnel are accurate, complete, and verifiable from 
source documents; that the safety and rights of participants are being protected; and that 
the study is being conducted in accordance with the currently approved protocol and any 
other study agreements, ICH GCP, and all applicable regulatory requirements. 
• Records and documents, including signed ICFs, pertaining to the conduct of this study 
must be retained by the Investigator for 2 years after study completion unless local 
regulations or institutional policies require a longer retention period. No records may be 
destroyed during the retention period without the written approval of the Sponsor. No 
records may be transferred to another location or party without written notification to the 
Sponsor. 
Quality assurance includes all the planned and systematic actions that are established to ensure 
that the clinical study is performed and the data are generated, documented (recorded), and 
reported according to ICH GCP and local/regional regulatory standards. 
A quality assurance representative from Sponsor or qualified designee, who is independent of 
and separated from routine monitoring, may periodically arrange inspections/audits of the 
clinical study by reviewing the data obtained and procedural aspects. These inspections may 
include on-site inspections/audits and source data checks. Direct access to source documents is 
required for the purpose of these periodic inspections/audits.  
11.1.14. 
Data Collection and Management  
This study will be conducted in compliance with ICH CGP guidelines. This study will also be 
conducted in accordance with the most recent version of the Declaration of Helsinki.  
This study will use electronic data collection (to collect data directly from the investigational site 
using eCRFs. The Investigator is responsible for ensuring that all sections of each eCRF are 
completed promptly and correctly and that entries can be verified against any source data.  
Study monitors will perform source document verification to identify inconsistencies between 
the eCRFs and source documents. Discrepancies will be resolved in accordance with the 
principles of GCP. Detailed study monitoring procedures are provided in the Clinical Monitoring 
Plan. 
Adverse events will be coded with MedDRA. Concomitant medications will be coded using 
World Health Organization – Drug Reference List.  

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11.1.15. 
Source Documents 
Source documents are original documents or certified copies, and include, but are not limited to, 
diary cards, medical and hospital records, screening logs, informed consent/assent forms, 
telephone contact logs, and worksheets. Source documents provide evidence for the existence of 
the participant and substantiate the integrity of the data collected. Source documents are filed at 
the Investigator’s site. 
Data reported on the CRF or entered in the eCRF that are transcribed from source documents 
must be consistent with the source documents or the discrepancies must be explained. The 
Investigator may need to request previous medical records or transfer records, depending on the 
study. Also, current medical records must be available. 
ModernaTX, Inc. or its designee requires that the Investigator prepare and maintain adequate and 
accurate records for each participant treated with the study intervention. Source documents such 
as any hospital, clinic, or office charts and the signed ICFs are to be included in the 
Investigator’s files with the participant’s study records. 
11.1.16. 
Retention of Records 
The Principal Investigator must maintain all documentation relating to the study for a period of 
at least 2 years after the last marketing application approval or, if not approved, 2 years 
following the discontinuance of the test article for investigation. If this requirement differs from 
any local regulations, the local regulations will take precedence unless the local retention policy 
is less than 2 years. 
If it becomes necessary for ModernaTX, Inc. or the regulatory authority to review any 
documentation relating to the study, the Investigator must permit access to such records. No 
records will be destroyed without the written consent of the Sponsor, if applicable. It is the 
responsibility of the Sponsor to inform the Investigator when these documents no longer need to 
be retained. 
11.1.17. 
Study and Site Closure 
If the study is prematurely terminated or suspended, the Sponsor shall promptly inform the 
Investigators, the IECs/IRBs, the regulatory authorities, and any contract research 
organization(s) used in the study of the reason for termination or suspension, as specified by the 
applicable regulatory requirements. The Investigator shall promptly inform the participant and 
should assure appropriate participant therapy and/or follow-up. 
The Sponsor or designee reserves the right to close the study site or terminate the study at any 
time for any reason at the sole discretion of the Sponsor.  
The Investigator may initiate study-site closure at any time, provided there is reasonable cause 
and sufficient notice is given in advance of the intended termination.  
Reasons for the early closure of a study site by the Sponsor or Investigator may include but are 
not limited to: 
• Continuation of the study represents a significant medical risk to participants. 

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• Failure of the Investigator to comply with the protocol, the requirements of the IRB/IEC 
or local health authorities, the Sponsor's procedures, or GCP guidelines. 
• Inadequate recruitment of participants by the Investigator. 
• Discontinuation of further mRNA-1010 development. 
Study sites will be closed upon study completion. A study site is considered closed when all 
required documents and study supplies have been collected and a study-site closure visit has 
been performed. 
11.1.18. 
Publication Policy 
The results of this study may be published or presented at scientific meetings. If this is foreseen, 
the Investigator agrees to submit all manuscripts or abstracts to the Sponsor before submission. 
This allows the Sponsor to protect proprietary information and to provide comments. 
The Sponsor will comply with the requirements for publication of study results. In accordance 
with standard editorial and ethical practice, the Sponsor will generally support publication of 
multicenter studies only in their entirety and not as individual site data. In this case, a 
coordinating Investigator will be designated by mutual agreement. 
Authorship will be determined by mutual agreement and in line with International Committee of 
Medical Journal Editors authorship requirements.] 
The clinical study plan and the results of the study will be published on www.ClinicalTrials.gov 
in accordance with 21 CFR 50.25(c). The results of and data from this study belong to 
ModernaTX, Inc.  

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11.2. 
APPENDIX 2: Contraceptive Guidance  
Definitions: Woman of Childbearing Potential (WOCBP) 
Women in the following categories are considered WOCBP (fertile): 
1. Following menarche 
2. From the time of menarche until becoming postmenopausal unless permanently sterile 
(see below). 
• A postmenopausal state is defined as no menses for 12 months without an alternative 
medical cause. 
o A high follicle-stimulating hormone (FSH) level in the postmenopausal range may be 
used to confirm a postmenopausal state in women not using hormonal contraception 
or hormonal replacement therapy (HRT). However, in the absence of 12 months of 
amenorrhea, confirmation with more than one FSH measurement is required.  
o Females on HRT and whose menopausal status is in doubt will be required to use one 
of the nonestrogen hormonal highly effective contraception methods if they wish to 
continue their HRT during the study. Otherwise, they must discontinue HRT to allow 
confirmation of postmenopausal status before study enrollment. 
• Permanent sterilization methods (for the purpose of this study) include: 
o Documented hysterectomy 
o Documented bilateral salpingectomy 
o Documented bilateral oophorectomy 
o Documented tubal ligation 
o For individuals with permanent infertility due to an alternate medical cause other than 
the above, (eg, Mullerian agenesis, androgen insensitivity, gonadal dysgenesis), 
Investigator discretion should be applied to determining study entry. 
Note: Documentation can come from the site personnel’s review of the participant’s medical 
records, medical examination, or medical history interview. 
• If fertility is unclear (eg, amenorrhea in adolescents or athletes) and a menstrual cycle 
cannot be confirmed before first dose of study intervention, additional evaluation should 
be considered. 
Contraception Guidance: 
Adequate female contraception is defined as consistent and correct use of a regulatory 
agency-approved contraceptive method in accordance with the product label (see Section 
11.6 for country-specific amendment affecting this section). For example: 
• Barrier method (such as condoms, diaphragm, or cervical cap) 
• Intrauterine device 
• Prescription hormonal contraceptive taken or administered via oral (pill), transdermal 
(patch), subdermal, or IM route 

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• Sterilization of a female participant's monogamous male partner prior to entry into the 
study 
Note: periodic abstinence (eg, calendar, ovulation, symptothermal, post-ovulation methods) and 
withdrawal are not acceptable methods of contraception. The above applies to females of 
child-bearing potential who are sexually active with male partners and not to females with same 
sex partners or those who are not sexually active as their usual lifestyle.

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11.3. 
APPENDIX 3: Estimands and Estimand Specifications 
Table 9: 
Intercurrent Event Types 
Label 
Intercurrent Event 
Type 
Comment 
IcEv1 (early discontinuation or 
death without confirmation of 
cases, ie, unrelated death) 
Unrelated death 
without documented 
influenza 
Participants in PP Set who withdraw 
consent or die due to reasons unrelated 
to influenza will be included in primary 
efficacy analysis. 
IcEv2 (early infection) 
Infection starting up to 
14 days after the study 
intervention 
Participants in PP Set who experience an 
early influenza infection up to 14 days 
after the IP will be included in primary 
efficacy analysis. 
Abbreviation: IcEv: intercurrent event, PP: per-protocol, FAS: full analysis set, mITT: modified intent-to-treat. 
Table 10: Primary Objective and Estimands with Rationale for Strategies to Address 
Intercurrent Events for Per-Protocol Analysis 
Objective: To demonstrate the efficacy of mRNA-1010 to prevent influenza 
Estimand Description 
Vaccine efficacy will be measured using 1 – HR (mRNA-1010/ 
Fluarix) from 14 days after study intervention. A hypothetical 
strategy will be used for early discontinuation (eg, withdrawal 
consent, deaths unrelated to influenza) or early infection in 
participants in PP Set. 
Target Population 
Adults aged 50 years and older 
Variable/Endpoint 
Time to first episode of RT-PCR confirmed protocol-defined ILI, 
censoring at early discontinuation, early infection, or last assessment 
for an event not being observed, whichever comes earlier. 
Treatment Condition(s) 
Test: mRNA-1010 
Reference: Active Comparator (Fluarix®) 
Estimand Label 
Estimand 1 
Population-Level Summary 
Vaccine efficacy defined as 1 - HR of mRNA-1010/active 
comparator 
Intercurrent Event Strategy 
 
IcEv1 (Early discontinuation 
or unrelated death): 
Hypothetical 
IcEv2 (early infection): 
Hypothetical 
Rationale for Strategy(s) 
Hypothetical: early discontinuation (including unrelated death) 
censored at time of discontinuation (or at time of death), and early 
case will be censored at the time at case onset, handled with 
independent censoring. 
Abbreviation: HR = Hazard ratio; IcEv: intercurrent event; ILI = Influenza like illness; RT-PCR = Reverse 
transcription polymerase chain reaction 
 

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11.4. 
APPENDIX 4: Adverse Events of Special Interest Terms 
Investigators should report all events that fall into the categories presented in Table 11 as an 
AESI per the reporting processes in Section 8.9.8. These AESIs are medical concepts that are 
generally of interest in vaccine safety surveillance as per the Brighton Collaboration and Safety 
Platform for Emergency Vaccines. 
Table 11: 
Adverse Events of Special Interest 
Medical Concept 
Additional Notes 
Thrombocytopenia 
• 
Platelet counts < 150 × 109  
• 
Including but not limited to immune thrombocytopenia, 
platelet production decreased, thrombocytopenia, 
thrombocytopenic purpura, thrombotic thrombocytopenic 
purpura, or HELLP syndrome 
New onset of or worsening of 
the following neurologic 
diseases: 
• 
Guillain-Barre Syndrome 
• 
Acute disseminated encephalomyelitis 
• 
Idiopathic peripheral facial nerve palsy (Bell’s palsy) 
• 
Seizures including but not limited to febrile seizures and/or 
generalized seizures/convulsions 
Anaphylaxis 
• 
Anaphylaxis as defined per protocol (Section 8.10.6.1) 
• 
Follow reporting procedures in Section 8.9.8 
Myocarditis/Pericarditis 
• 
Myocarditis 
• 
Pericarditis 
• 
Myopericarditis 
Abbreviation: HELLP = hemolysis, elevated liver enzymes, and low platelet count. 
 

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11.5. 
APPENDIX 5: CDC Working Case Definitions of Pericarditis, 
Myocarditis, and Myopericarditis Occurring After Receipt of 
COVID-19 mRNA Vaccines 
Table 12: 
Case Definitions of Probable and Confirmed Myocarditis, Pericarditis, and 
Myopericarditis 
Condition 
Definition 
Acute 
myocarditis 
Probable case 
Confirmed case 
Presence of ≥ 1 new or worsening of 
the following clinical symptoms:* 
• 
Chest pain, pressure, or 
discomfort. 
• 
Dyspnea, shortness of breath, or 
pain with breathing. 
• 
Palpitations. 
• 
syncope. 
Presence of ≥ 1 new or worsening of the 
following clinical symptoms:* 
• 
chest pain, pressure, or discomfort. 
• 
dyspnea, shortness of breath, or pain 
with breathing. 
• 
Palpitations. 
• 
Syncope. 
OR, infants and children aged 
< 12 years might instead have ≥ 2 of 
the following symptoms: 
• 
irritability. 
• 
vomiting. 
• 
poor feeding. 
• 
tachypnea. 
• 
lethargy. 
OR, infants and children aged < 12 years 
might instead have ≥ 2 of the following 
symptoms: 
• 
Irritability. 
• 
vomiting. 
• 
poor feeding. 
• 
tachypnea. 
• 
Lethargy. 
AND 
≥ 1 new finding of 
• 
troponin level above upper limit of 
normal (any type of troponin). 
• 
abnormal electrocardiogram (ECG 
or EKG) or rhythm monitoring 
findings consistent with 
myocarditis§. 
• 
abnormal cardiac function or wall 
motion abnormalities on 
echocardiogram. 
• 
cMRI findings consistent with 
myocarditis¶. 
AND 
≥ 1 new finding of 
• 
Histopathologic confirmation of 
myocarditis†. 
• 
cMRI findings consistent with 
myocarditis¶ in the presence of 
troponin level above upper limit of 
normal (any type of troponin). 
AND 
• 
No other identifiable cause of the 
symptoms and findings. 
AND 
• 
No other identifiable cause of the 
symptoms and findings. 

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Acute 
pericarditis** 
Presence of ≥ 2 new or worsening of the following clinical features: 
• 
acute chest pain††. 
• 
pericardial rub on exam. 
• 
new ST-elevation or PR-depression on EKG. 
• 
new or worsening pericardial effusion on echocardiogram or MRI. 
Myopericarditis 
This term may be used for patients who meet criteria for both myocarditis and 
pericarditis. 
Abbreviations : CDC = Centers for Disease Control and Prevention; CEAC = Cardiac Event Adjudication 
Committee; cMRI = cardiac magnetic resonance imaging; ECG or EKG = electrocardiogram; MRI = magnetic 
resonance imaging. 
Note: An independent CEAC comprised of medically qualified personnel, including cardiologists, will review 
suspected cases of myocarditis, pericarditis, and myopericarditis to determine if they meet Center for Disease 
Control and Prevention criteria for “probable” or “confirmed” events, (Gargano et al 2021), and provide the 
assessment to the Sponsor. The CEAC members will be blinded to study treatment. Details regarding the CEAC 
composition, responsibilities, procedures, and frequency of data review will be defined in the CEAC charter. 
 * Persons who lack the listed symptoms but who meet other criteria may be classified as subclinical myocarditis 
(probable or confirmed). 
 † Using the Dallas criteria (Aretz et al 1987). Autopsy cases may be classified as confirmed clinical myocarditis 
on the basis of meeting histopathologic criteria if no other identifiable cause. 
 § To meet the ECG or rhythm monitoring criterion, a probable case must include at least one of 1) ST-segment or 
T-wave abnormalities; 2) Paroxysmal or sustained atrial, supraventricular, or ventricular arrhythmias; or 3) AV 
nodal conduction delays or intraventricular conduction defects. 
 ¶ Using either the original or the revised Lake Louise criteria. 
https://www.sciencedirect.com/science/article/pii/S0735109718388430?via%3Dihubexternal icon 
 ** https://academic.oup.com/eurheartj/article/36/42/2921/2293375external icon 
 †† Typically described as pain made worse by lying down, deep inspiration, or cough, and relieved by sitting up or 
leaning forward, although other types of chest pain might occur. 
Reference: (Gargano et al 2021). 
 

ModernaTX, Inc. 
Protocol mRNA-1010-P302 Amendment 1 
mRNA-1010 
Confidential 
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11.6. 
APPENDIX 6: Country-specific Requirements 
11.6.1. 
Protocol Amendment DNK-1 (Danish Country-specific Requirements), 26 Oct 
2022 
Country-specific requirements for the Danish Medicines Agency are as follows: 
• Section 5.1, Inclusion Criteria, and Appendix 2, Contraception Guidance, changed the 
term “adequate contraception” to “highly effective contraceptive methods.” 
• Section 8.10.2, Serious Adverse Events, revised the definition of serious adverse events 
as follows: Persistent or significant disability or incapacity or substantial disruption of 
the ability to conduct normal life functions. 
• Section 9.5.1.1, Analysis of Primary Efficacy Endpoint, now includes the following 
summary description for how missing data will be handled: Participants without RT-
PCR–confirmed protocol-defined ILI will be censored at Day 181 (Month 6) or end of 
influenza season (whichever occurs later), or at the date of early discontinuation or death 
unrelated to influenza, whichever is earlier. Participants with early RT-PCR–confirmed 
protocol-defined ILI up to 14 days after the study vaccination will be censored at the start 
date of the early RT-PCR–confirmed protocol-defined ILI. 
11.6.2. 
Protocol Amendment GBR-1 (United Kingdom Country-specific Requirements), 
22 Sep 2022 
Country-specific requirements for the Medicines and Healthcare products Regulatory Agency are 
as follows: 
• Section 6.3.7, Unblinding, removed text that stated the requirement of the Investigator to 
promptly contact the CRO clinical research associate with an explanation for unblinding 
within 24 hours of opening the code. 

Signature Page for VV-CLIN-005361 v2.0
Signature Page for VV-CLIN-005361 v2.0
2nd Approval
03-Feb-2023 21:49:07 GMT+0000
PPD