A Phase 1/2, Randomized, Open-Label Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1 Candidate Seasonal Influenza Vaccines in Healthy Adults 50 to 75 Years of Age
Phase: PHASE1
Conditions: Seasonal Influenza
Sponsor: ModernaTX, Inc.

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mRNA-1011-P101 Clinical Study Protocol 
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CLINICAL STUDY PROTOCOL 
Protocol Title: 
A Phase 1/2, randomized, open‑label study to evaluate the 
safety, reactogenicity, and immunogenicity of mRNA-1011.1, 
mRNA-1011.2, and mRNA-1012.1 candidate seasonal influenza 
vaccines in healthy adults 50 to 75 years of age 
Protocol Number: 
mRNA-1011-P101 
Sponsor Name: 
ModernaTX, Inc.  
Legal Registered Address: 
200 Technology Square 
Cambridge, MA 02139 
Sponsor Contact and 
Medical Monitor: 
 
 
ModernaTX, Inc. 
200 Technology Square 
Cambridge, MA 02139 
Telephone: 
 
e-mail: 
Regulatory Agency 
Identifier Numbers: 
Not yet available 
Date of Original Protocol: 
03 Jan 2023 
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. 
NCT05827068
PPD
PPD
PPD

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PROTOCOL APPROVAL – SPONSOR SIGNATORY 
Study Title: 
A Phase 1/2, randomized, open-label study to evaluate the safety, 
reactogenicity, and immunogenicity of mRNA-1011.1, 
mRNA-1011.2, and mRNA-1012.1 candidate seasonal influenza 
vaccines in healthy adults 50 to 75 years of age 
Protocol Number: 
mRNA-1011-P101 
Approval Date: 
03 Jan 2023 
 
 
 
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

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mRNA-1011-P101 Clinical Study Protocol 
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DECLARATION OF INVESTIGATOR 
I have read and understood all sections of the protocol entitled “A Phase 1/2, randomized, 
open‑label study to evaluate the safety, reactogenicity, and immunogenicity of mRNA-1011.1, 
mRNA-1011.2, and mRNA-1012.1 candidate seasonal influenza vaccines in healthy adults 50 to 
75 years of age” dated 03 Jan 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 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. 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  
 
 
 
 

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1. 
PROTOCOL SUMMARY 
1.1. 
Synopsis 
Name of Sponsor/Company: ModernaTX, Inc. 
Name of Investigational Products: mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1, and 
mRNA-1010 products (mRNA-1010, mRNA-1010.2 and mRNA-1010.3) 
Protocol Number: mRNA-1011-P101 
Protocol Title: A Phase 1/2, randomized, open-label study to evaluate the safety, reactogenicity, 
and immunogenicity of mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1 candidate seasonal 
influenza vaccines in healthy adults 50 to 75 years of age 
Brief Title: A Phase 1/2 study to evaluate the safety, reactogenicity, and immunogenicity of 
mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1 influenza vaccines in healthy adults 
50 to 75 years of age 
Regulatory Agency Identifier Number: Not yet available 
Background and Rationale: 
Currently licensed seasonal influenza virus vaccines have suboptimal efficacy, rarely exceed 
50% overall effectiveness, and are poorly effective during years when the circulating viruses do 
not match the strains selected for the vaccine antigens (CDC 2020). Influenza vaccines based on 
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, potential for stronger immune responses, as 
well as improved protection in older adults (Rockman et al 2020).  
Current quadrivalent seasonal influenza vaccines are manufactured to prevent influenza illness 
caused by 4 influenza strains that include 2 influenza A strains (A/H1N1 and A/H3N2) and 2 
influenza B strains (B/Yamagata and B/Victoria). However, influenza A/H3N2 remains the 
major driver of influenza-related hospitalizations and deaths, particularly in older adults. Lower 
vaccine effectiveness against the influenza A/H3N2 viruses may be in part caused by vaccine 
mismatches that can occur due to co-circulation of multiple different A/H3N2 clades, whereas 
only one of those clades is generally covered by the vaccine. The inclusion of additional strains 
could allow for expanded coverage against multiple co-circulating A/H3N2 strains of distinct 
antigenic clades in influenza vaccination programs; and furthermore, enable public health 
authorities to recommend a higher number of strains for inclusion into the vaccine. 
The Sponsor is conducting this Phase 1/2 study to evaluate safety and immunogenicity of 3 
next‑generation seasonal influenza mRNA vaccines with coverage for more than one A/H3N2 
strain (mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1) compared to the quadrivalent 
mRNA-1010 vaccine with coverage for 1 A/H3N2 strain. mRNA-1011.1 contains 5 mRNAs 
encoding hemagglutinin antigens (HAs) for A/H1N1, B/Victoria, B/Yamagata, and two A/H3N2 
strains, while mRNA-1011.2 contains 4 mRNAs encoding HAs similar to mRNA-1011.1 
(including coverage for two A/H3N2 strains) but with B/Yamagata excluded. The rationale for 
excluding B/Yamagata is due to the lack of circulation of B/Yamagata-lineage viruses in recent 
years and thus, allowing for a higher proportion of other strains to be represented in the vaccine 

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within the same total mRNA dose. mRNA-1012.1 contains 5 mRNAs encoding HAs similar to 
1011.2 but with 1 additional HA from the A/H3N2 lineages (coverage for three A/H3N2 strains). 
The comparator mRNA-1010 vaccine is the Sponsor’s first-generation quadrivalent vaccine 
containing HAs from A/H1N1, B/Yamagata, B/Victoria, and 1 of three A/H3N2 lineages that 
matches those in the next-generation vaccines (mRNA-1010, mRNA-1010.2, and 
mRNA‑1010.3). The mRNA-1010 vaccine is currently under investigation in an ongoing Phase 3 
immunogenicity study in adults ≥18 years of age (NCT05415462) and Phase 3 efficacy study in 
adults ≥50 years of age (NCT05566639). 
The objective of the study (mRNA-1011-P101) is to establish preliminary safety and 
immunogenicity data to support selection of a lead candidate for initiation of pivotal studies. The 
mRNA-1011.1, mRNA-1011.2, mRNA-1012.1, and mRNA-1010 (mRNA-1010, mRNA‑1010.2, 
and mRNA-1010.3) development candidates are administered as a single dose and are aimed to 
elicit protection from all seasonal influenza viruses covered by the candidate vaccines. 
The study design has safety and reactogenicity evaluation as the primary objective, with a 
secondary objective of evaluating immunogenicity for each HA component using the HAI assay, 
because HAI titers have been established as a correlate of protection against influenza illness. 
The rationale for this approach is based on the established precedent of using HA-based 
immunologic correlates for clinical assessment and licensure of influenza vaccines 
(DHHS 2007a; EMA Guidance 2016; Dunning et al 2016). 
Objectives and Endpoints 
Objectives 
Endpoints 
Primary 
• To evaluate the safety and 
reactogenicity of mRNA-1011.1, 
mRNA-1011.2, mRNA-1012.1, 
and mRNA-1010 controls 
(mRNA-1010, mRNA-1010.2 and 
mRNA-1010.3) 
• Solicited local and systemic ARs 
through 7 days after injection 
• Unsolicited AEs through 28 days 
after injection 
• MAAEs from Day 1 to Day 181/EoS 
• AESIs from Day 1 to Day 181/EoS 
• SAEs from Day 1 to Day 181/EoS 
• AEs leading to discontinuation from 
Day 1 to Day 181/EoS 
Secondary 
• To evaluate the humoral 
immunogenicity of mRNA-
1011.1, mRNA-1011.2, mRNA-
1012.1 in comparison with 
mRNA-1010 controls (mRNA-
1010, mRNA-1010.2 and mRNA-
1010.3) against vaccine-matched 
• GMT and GMFR, comparing Day 29 
with Day 1 (baseline), and percentage 
of participants with seroconversion, 
defined as a postbaseline titer ≥1:40 
if baseline is <1:10 or a 4-fold or 
greater rise if baseline is ≥1:10 in 

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Objectives 
Endpoints 
influenza A and B strains at Day 
29 
anti-HA antibodies measured by HAI 
assay 
Abbreviations: AE = adverse event; AESI = adverse event of special interest; EoS = end of study; GMFR = 
geometric mean fold rise; GMT = geometric mean titer; HA = hemagglutinin; HAI = hemagglutination inhibition; 
MAAE = medically attended adverse event; mRNA = messenger ribonucleic acid; SAE = serious adverse event.

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Overall Study Design 
This prospective, open-label Phase 1/2 study will enroll approximately 700 healthy adults 
≥50 to ≤75 years of age. Participants will be stratified by prior season influenza vaccination 
status; those who received a licensed or investigational influenza vaccine within 180 days prior 
to enrollment will be excluded. Different dose levels will be assessed in parallel across 7 
treatment arms. Each participant will receive a single injection administered intramuscularly in 
the deltoid muscle and will be followed for 6 months post vaccination.  
Brief Summary 
The purpose of this study is to measure the safety and the immune response to 3 next-generation 
influenza vaccine candidates (mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1) compared 
with influenza vaccine candidate mRNA-1010 controls in healthy adult participants. The study 
duration will be up to 7 months including screening. The treatment will be administered as a 
single dose on Day 1.  
Key study details include: 
• Screening Visit (up to 28 days before the Day 1 visit). 
• Randomization Visit at Day 1 (Baseline). 
• Subsequent study visits will occur on Day 8, Day 29 (Month 1), and Day 181 (Month 
6)/EoS. 
• Five safety telephone call visits at Days 15, 57, 91, 121, and 151 will be conducted. 
• Unscheduled visits for protocol-defined influenza-like illness (ILI) symptoms. 
Symptom assessment and collection of NP sample should be performed ≤7 days from 
onset of ILI symptoms. 
• All participants will be asked to complete an eDiary for solicited ARs from Day 1 to 
Day 7. 
Number of Participants: Approximately 700 participants will be enrolled into 7 treatment arms. 
Note: Enrolled means participants agree to participate in a clinical study 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. 
Study Arms and Duration: 
• The study comprises 7 treatment arms of different dose levels of drug products with 
6-month follow-up post vaccination. 
• The total duration (including screening) for each participant is up to 7 months. 
 

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1.2. 
Schema 
Figure 1: 
Study Schema 
 
Abbreviation: C = Clinic; D = Day; mRNA = Messenger ribonucleic acid; N = Number of participants; SC = Safety Call; V = Visit 

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1.3. 
Schedule of Events 
Table 1: 
Schedule of Events 
Visit Number 
SCRN 
1 
2 
3 
4 
5, 6, 7, 8 
9 
USV 
Type of Visit 
C 
C 
C 
SC 
C 
SC 
C 
C 
Month Timepoint 
 
 
 
 
M1 
M2, M3, 
M4, M5 
M6 
Up to M6 
Visit Day  
Screeninga 
D1 
(Baseline)a 
D8 
D15 
D29 
D57, D91, 
D121, D151 
D181/ 
EoS 
N/A 
Window Allowance (Days) 
-28 
- 
-1/+3 
±3 
-7/+3 
±5 
±14 
N/A 
Informed consent form, demographics, 
concomitant medications, medical history 
X 
 
 
 
 
 
 
 
Inclusion/exclusion criteria 
X 
X 
 
 
 
 
 
 
Blood collection for safety laboratory samplesb 
X 
 
X 
 
 
 
 
 
Physical examinationc 
X 
X 
X 
 
X 
 
X 
X 
Injection site and corresponding draining lymph 
nodes assessmentd 
 
X 
 
 
 
 
 
 
Vital sign measurementse 
X 
X 
 
 
 
 
 
 
Pregnancy testingf 
X 
X 
 
 
 
 
 
 
Randomization 
 
X 
 
 
 
 
 
 
Study vaccination (including 60-minute, 
postdose observation period) 
 
Xg 
 
 
 
 
 
 
Blood collection for humoral immunogenicityh 
 
X 
 
 
X 
 
X 
 
Blood collection for cellular immunogenicityh 
 
X 
 
 
X 
 
 
 
Optional blood collection for genomicsi 
 
X 
 
 
 
 
 
 
Optional blood collection for transcriptomicsi 
 
X 
X 
 
X 
 
 
 

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Visit Number 
SCRN 
1 
2 
3 
4 
5, 6, 7, 8 
9 
USV 
Type of Visit 
C 
C 
C 
SC 
C 
SC 
C 
C 
Month Timepoint 
 
 
 
 
M1 
M2, M3, 
M4, M5 
M6 
Up to M6 
Visit Day  
Screeninga 
D1 
(Baseline)a 
D8 
D15 
D29 
D57, D91, 
D121, D151 
D181/ 
EoS 
N/A 
Window Allowance (Days) 
-28 
- 
-1/+3 
±3 
-7/+3 
±5 
±14 
N/A 
Nasopharyngeal swab for virus detectionj 
 
X 
 
 
 
 
 
X 
eDiary activation for recording solicited ARs 
(7 days)k 
 
X 
 
 
 
 
 
 
Review of solicited AR eDiary 
 
 
X 
 
 
 
 
 
Follow-up safety calll 
 
 
 
X 
 
X 
 
 
Recording of unsolicited AEs through Day 29 
and concomitant medications 
 
X 
X 
X 
X 
 
 
X 
Recording of SAEs, AESIs, MAAEs, AEs 
leading to discontinuation, and concomitant 
medications relevant to or for their treatment 
 
X 
X 
X 
X 
X 
X 
X 
Recording of nonstudy vaccinations 
X 
X 
X 
X 
X 
X 
X 
 
Study completion 
 
 
 
 
 
 
X 
 
Abbreviations: AE = adverse event; AESI = adverse event of special interest; ALT = alanine aminotransferase; AR = adverse reaction; AST = aspartate 
aminotransferase; C = clinic visit; D = day; eDiary = electronic diary; EoS = end of study; FSH = follicle-stimulating hormone; HCP = health care practitioner; 
ILI = influenza-like illness; IM = intramuscular; M = month; MAAE = medically attended adverse event; N/A = not applicable; NP = nasopharyngeal; 
SAE = serious adverse event; SC = safety (telephone) call; SCRN = Screening; USV = unscheduled visit. 
a 
Screening and Day 1 cannot be performed on the same day. Additionally, the Screening Visit may be performed over multiple visits if within the 28-day 
Screening window. 
b 
Safety laboratory tests include total white blood cell count, hemoglobin, platelets, ALT, AST, creatinine, alkaline phosphatase, and total bilirubin. 
c 
A full physical examination, including height and weight, will be performed at Screening; symptom-directed physical examinations will be performed at 
other clinic visits. Interim physical examinations will be performed at the discretion of the Investigator. Any clinically significant finding identified by an 
HCP during clinic visits should be reported as a MAAE. 

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d 
Prior to injection on the day of vaccination (Day 1), the injection site and associated draining lymph nodes (ipsilateral axillary lymph nodes) should be 
examined, and any abnormalities should be documented. 
e 
Systolic and diastolic blood pressure, pulse rate, respiratory rate, and body temperature will be recorded as vital signs. The preferred route of temperature 
assessment is oral. Vital signs will only be collected at Screening and on the day of vaccination (Day 1), once before and at least 60 minutes after 
vaccination. Vital signs will be collected at other clinical visits only in conjunction with a symptom-directed physical examination. 
f 
A point-of-care urine pregnancy test will be performed at the Screening Visit and before the IM injection on Day 1. At the discretion of the Investigator, a 
pregnancy test either via blood or point-of-care urine can be performed at any time. The FSH level may be measured at the Screening Visit, if necessary and 
at the discretion of the Investigator, to confirm menopausal status.  
g 
All participants will be randomized to receive a single IM injection in the deltoid muscle. 
h 
Samples for humoral immunogenicity and cellular immunogenicity must be collected prior to receipt of vaccination on Day 1. Cellular immunogenicity will 
be sampled and assessed in a subset of approximately 15 to 20 participants per arm. 
i 
Transcriptomic and genomic samples will be part of the optional biomarker assessment once consented by participants. Blood draws on Day 1 must occur 
prior to participants being vaccinated. 
j 
An NP swab specimen for viral respiratory pathogens will be collected prior to the study intervention administration on Day 1. An NP swab should be 
collected through study completion for protocol-defined ILI ≤7 days of symptom onset. 
k 
The eDiary entries will be recorded by the participant starting approximately 60 minutes after vaccination while at the clinic with instruction provided by 
study staff. Study participants will continue to record in the eDiary each day after vaccination, on the day of vaccination and for subsequent 6 days following 
vaccination. 
l 
Trained study personnel will call all participants to collect information related to any SAEs, MAAEs, AESIs, or AEs leading to study discontinuation, with 
information on concomitant medications associated with those events, and any nonstudy vaccinations. 
 

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TABLE OF CONTENTS 
CLINICAL STUDY PROTOCOL ..................................................................................................1 
PROTOCOL APPROVAL – SPONSOR SIGNATORY ................................................................2 
DECLARATION OF INVESTIGATOR .........................................................................................3 
1. 
PROTOCOL SUMMARY ............................................................................................4 
1.1. 
Synopsis ........................................................................................................................4 
1.2. 
Schema ..........................................................................................................................8 
1.3. 
Schedule of Events .......................................................................................................9 
TABLE OF CONTENTS ...............................................................................................................12 
LIST OF TABLES .........................................................................................................................16 
LIST OF FIGURES .......................................................................................................................16 
LIST OF ABBREVIATIONS ........................................................................................................17 
2. 
INTRODUCTION ......................................................................................................20 
2.1. 
Study Rationale ...........................................................................................................20 
2.2. 
Background and Overview .........................................................................................21 
2.2.1. 
Nonclinical Studies .....................................................................................................22 
2.2.2. 
Clinical Studies ...........................................................................................................23 
2.3. 
Benefit/Risk Assessment ............................................................................................24 
2.3.1. 
Known Potential Benefits ...........................................................................................24 
2.3.2. 
Risks from Study Participation and Their Mitigation .................................................24 
2.3.3. 
Overall Benefit/Risk Conclusion ................................................................................25 
3. 
OBJECTIVES AND ENDPOINTS ............................................................................26 
4. 
STUDY DESIGN .......................................................................................................28 
4.1. 
General Design ...........................................................................................................28 
4.2. 
Scientific Rationale for Study Design ........................................................................29 
4.3. 
Justification for Dose ..................................................................................................30 
4.4. 
End of Study Definition ..............................................................................................30 
5. 
STUDY POPULATION .............................................................................................31 
5.1. 
Inclusion Criteria ........................................................................................................31 
5.2. 
Exclusion Criteria .......................................................................................................31 
5.3. 
Lifestyle Restrictions ..................................................................................................33 
5.4. 
Screen Failures ............................................................................................................33 

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6. 
STUDY INTERVENTIONS ......................................................................................34 
6.1. 
Study Interventions Administered ..............................................................................34 
6.2. 
Randomization ............................................................................................................34 
6.3. 
Preparation/Handling/Storage/Accountability ............................................................34 
6.3.1. 
Preparation of Study Intervention ...............................................................................34 
6.3.2. 
Study Intervention Administration .............................................................................34 
6.3.3. 
Study Intervention Delivery and Receipt ...................................................................35 
6.3.4. 
Study Intervention Packaging and Labeling ...............................................................35 
6.3.5. 
Study Intervention Storage .........................................................................................35 
6.3.6. 
Study Intervention Accountability ..............................................................................35 
6.3.7. 
Study Intervention Handling and Disposal .................................................................36 
6.4. 
Study Intervention Compliance ..................................................................................36 
6.5. 
Dose Modification ......................................................................................................36 
6.6. 
Continued Access to Study Intervention after the End of the Study ..........................36 
6.7. 
Prior and Concomitant Therapy ..................................................................................36 
6.7.1. 
Prior Medications and Therapies ................................................................................36 
6.7.2. 
Concomitant Medications and Vaccinations ...............................................................36 
6.7.3. 
Concomitant Medications and Vaccines that May Lead to the Elimination of 
a Participant from Per-Protocol Analyses ....................................................................37 
7. 
DELAY OR DISCONTINUATION OF STUDY INTERVENTION AND 
PARTICIPANT DISCONTINUATION/WITHDRAWAL .......................................38 
7.1. 
Pause Rules .................................................................................................................38 
7.1.1. 
Pause Rules Based on the Occurrence of a Single Event and Adjudicated by 
the Data Safety Monitoring Board ..............................................................................38 
7.2. 
Criteria for Delay or Withholding of Study Intervention ...........................................39 
7.3. 
Participant Discontinuation/Withdrawal from the Study ...........................................40 
7.4. 
Lost to Follow-up .......................................................................................................41 
8. 
STUDY ASSESSMENTS AND PROCEDURES ......................................................42 
8.1. 
Study Vaccine Administration ....................................................................................42 
8.2. 
Safety Assessments and Procedures ...........................................................................42 
8.2.1. 
Physical Examination and Vital Signs ........................................................................43 
8.2.2. 
Pregnancy Testing ......................................................................................................43 
8.2.3. 
Assessments for Respiratory Viral Infections ............................................................44 

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8.2.4. 
Safety Telephone Calls ...............................................................................................44 
8.2.5. 
Use of Electronic Diaries ............................................................................................44 
8.2.6. 
Recording and Follow-up of Pregnancy .....................................................................45 
8.2.7. 
Recording and Follow-up of an AE and/or SAE ........................................................45 
8.2.8. 
Reporting Adverse Events ..........................................................................................46 
8.2.9. 
Reporting Serious Adverse Events .............................................................................46 
8.2.10. 
Time Period and Frequency for Collecting AE and SAE Information .......................47 
8.2.11. 
Method of Detecting AEs and SAEs ..........................................................................47 
8.2.12. 
Safety Laboratory Assessments ..................................................................................47 
8.2.13. 
Blood Sampling Volumes ...........................................................................................48 
8.2.14. 
Ancillary Supplies for Participant Use .......................................................................48 
8.3. 
Immunogenicity Assessments ....................................................................................48 
8.4. 
Safety Definitions and Related Procedures ................................................................48 
8.4.1. 
Influenza-Like Illness Case Definitions .....................................................................48 
8.4.2. 
Adverse Event .............................................................................................................49 
8.4.3. 
Serious Adverse Events ..............................................................................................50 
8.4.4. 
Solicited Adverse Reactions .......................................................................................51 
8.4.5. 
Medically Attended Adverse Events ..........................................................................53 
8.4.6. 
Adverse Events of Special Interest .............................................................................53 
8.4.7. 
Assessment of Intensity/Severity ................................................................................55 
8.4.8. 
Assessment of Causality .............................................................................................55 
8.4.9. 
Regulatory Reporting Requirements for SAEs ...........................................................56 
8.5. 
Safety Oversight .........................................................................................................56 
8.5.1. 
Internal Safety Team ...................................................................................................56 
8.5.2. 
Independent Cardiac Event Adjudication Committee ................................................56 
8.6. 
Treatment of Overdose ...............................................................................................57 
8.7. 
Pharmacokinetics ........................................................................................................57 
8.8. 
Pharmacodynamics .....................................................................................................57 
8.9. 
Biomarkers ..................................................................................................................57 
8.10. 
Health Economics .......................................................................................................57 
9. 
STATISTICAL CONSIDERATIONS .......................................................................58 
9.1. 
Blinding and Responsibility for Analyses ..................................................................58 
9.2. 
Statistical Hypotheses .................................................................................................58 

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9.3. 
Sample Size Determination ........................................................................................58 
9.4. 
Analysis Populations ..................................................................................................59 
9.5. 
Statistical Methods ......................................................................................................59 
9.5.1. 
Baseline Characteristics and Demographics ...............................................................59 
9.5.2. 
Safety Analyses ..........................................................................................................59 
9.5.3. 
Immunogenicity Analyses ..........................................................................................60 
9.5.4. 
Exploratory Analyses ..................................................................................................61 
9.5.5. 
Subgroup Analyses .....................................................................................................61 
9.6. 
Planned Analyses ........................................................................................................61 
9.6.1. 
Interim Analyses .........................................................................................................61 
10. 
REFERENCES ...........................................................................................................62 
11. 
SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS ..................................................................................................64 
11.1. 
APPENDIX 1: Study Governance Considerations .....................................................65 
11.1.1. 
Regulatory and Ethical Considerations ......................................................................65 
11.1.2. 
Study Monitoring ........................................................................................................65 
11.1.3. 
Audits and Inspections ................................................................................................66 
11.1.4. 
Financial Disclosure ...................................................................................................67 
11.1.5. 
Recruitment Strategy ..................................................................................................67 
11.1.6. 
Informed Consent Process ..........................................................................................67 
11.1.7. 
Data Protection ...........................................................................................................68 
11.1.8. 
Sample Retention and Future Biomedical Research ..................................................69 
11.1.9. 
Dissemination of Clinical Study Data ........................................................................69 
11.1.10. 
Data Quality Assurance and Quality Control .............................................................69 
11.1.11. 
Source Documents ......................................................................................................70 
11.1.12. 
Retention of Records ..................................................................................................71 
11.1.13. 
Study and Site Closure................................................................................................71 
11.1.14. 
Publication Policy .......................................................................................................72 
11.2. 
APPENDIX 2: Contraceptive Guidance .....................................................................73 
11.3. 
APPENDIX 3: Adverse Events of Special Interest Terms .........................................75 
11.4. 
APPENDIX 4: CDC Working Case Definition of Pericarditis, Myocarditis, 
and Myopericarditis Occurring after Receipt of COVID-19 mRNA Vaccines ..........76 
 

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LIST OF TABLES 
Table 1: 
Schedule of Events .......................................................................................................9 
Table 2: 
Study Objectives and Endpoints .................................................................................26 
Table 3: 
Study Arms and Dose Levels .....................................................................................29 
Table 4: 
Pause Rule Criteria, Events, and Thresholds - Single Event ......................................38 
Table 5: 
Pause Rule Criteria, Events, and Thresholds – Proportion of Participants ................39 
Table 6: 
Respiratory and Systemic Symptoms for Protocol-defined Influenza-like 
Illness ..........................................................................................................................49 
Table 7: 
Solicited Adverse Reactions and Grades ....................................................................52 
Table 8: 
Probability of AEs Based on Sample Size ..................................................................58 
Table 9: 
Analysis Sets ...............................................................................................................59 
Table 10: Adverse Events of Special Interest .............................................................................75 
Table 11: Case Definitions of Probable and Confirmed Myocarditis, Pericarditis, and 
Myopericarditis ...........................................................................................................76 
 
LIST OF FIGURES 
Figure 1: 
Study Schema ...............................................................................................................8 
 
 

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LIST OF ABBREVIATIONS 
The following abbreviations and terms are used in this study protocol. 
Abbreviation or 
Specialist Term 
Definition 
AE 
Adverse event 
AESI 
Adverse events of special interest 
AR 
Adverse reactions 
CDC 
Centers for Disease Control and Prevention 
CEAC 
Cardiac Event Adjudication Committee 
CFR 
Code of Federal Regulations 
CI 
Confidence interval 
COVID-19 
Coronavirus disease 2019 
CRO 
Contract research organization 
DHHS 
Department of Health and Human Services 
DP 
Drug product 
ECG or EKG 
Electrocardiogram 
eCRF 
Electronic case report form 
eDiary 
Electronic diary 
EDC 
Electronic data capture 
EMA 
European Medicines Agency 
EoS 
End of study 
FAS 
Full Analysis Set 
FDA 
Food and Drug Administration 
FSH 
Follicle-stimulating hormone 
GCP 
Good Clinical Practice 
GLP 
Good Laboratory Practice 
GMFR 
Geometric mean fold rise 
GMP 
Good manufacturing practices 
GMT 
Geometric mean titer 
GMTR 
Geometric mean titer ratios 

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Abbreviation or 
Specialist Term 
Definition 
HA 
Hemagglutinin 
HAI 
Hemagglutination inhibition 
HCP 
Healthcare practitioner 
HRT 
Hormone replacement therapy 
IA 
Interim analysis 
IB 
Investigator’s brochure 
ICF 
Informed consent form 
ICH 
International Council for Harmonisation 
IEC 
Independent Ethics Committee 
IgG 
Immunoglobulin G 
ILI 
Influenza-like illness 
IM 
Intramuscular(ly) 
IP 
Investigational product 
IRB 
Institutional review board 
IRT 
Interactive response technology  
IST 
Internal safety team 
LLOQ 
Lower limit of quantification 
LNP 
Lipid nanoparticle 
LTFU 
Lost to follow-up 
MAAE 
Medically attended adverse event 
MedDRA 
Medical Dictionary for Regulatory Activities 
MN 
Microneutralization 
mRNA 
Messenger ribonucleic acid 
nAb 
Neutralizing antibody 
NH 
Northern hemisphere 
NP 
Nasopharyngeal 
PCR 
Polymerase chain reaction 
PP 
Per-protocol 

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Abbreviation or 
Specialist Term 
Definition 
QA 
Quality assurance 
RT-PCR 
Reverse transcription polymerase chain reaction 
SAE 
Serious adverse event 
SAP 
Statistical analysis plan 
SARS-CoV-2 
Severe acute respiratory syndrome coronavirus 2 
SH 
Southern hemisphere 
SM 
heptadecan-9-yl 8-((2-hydroxyethyl)(6-oxo-6 
(undecyloxy)hexyl)amino)octanoate 
SoE 
Schedule of Events 
ULOQ 
Upper limit of quantification 
US 
United States 
WHO 
World Health Organization 
WOCBP 
Woman of childbearing potential 

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2. 
INTRODUCTION 
2.1. 
Study Rationale 
Influenza A/H3N2 is a major driver of influenza-related hospitalizations and deaths, particularly 
in older adults. Lower vaccine efficacy against A/H3N2 viruses may contribute to the higher 
medical burden of influenza A. The inclusion of additional strains could allow for expanded 
coverage against multiple co-circulating A/H3N2 strains of distinct antigenic clades in influenza 
vaccination programs; and furthermore, enable public health authorities to recommend a higher 
number of strains for inclusion into the vaccine. Therefore, the Sponsor intends to evaluate 
mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1 vaccine candidates which include additional 
HAs from influenza A/H3N2 strains. mRNA-1010 vaccine, a quadrivalent HA investigational 
product, is currently under investigation in an ongoing Phase 3 immunogenicity study in adults 
≥18 years of age (NCT05415462) and a Phase 3 efficacy study in adults ≥50 years of age 
(NCT05566639). Three mRNA-1010 products (mRNA-1010, mRNA-1010.2, and 
mRNA‑1010.3) contain HA from different H3N2 strains to match the A/H3N2 strains in the 
experimental products and will serve as comparison controls for this study of next-generation 
influenza mRNA candidates. 
The Sponsor is conducting this Phase 1/2 study to evaluate safety and immunogenicity of 3 
next‑generation seasonal influenza mRNA vaccines with coverage for more than one A/H3N2 
strain (mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1) compared to the quadrivalent 
mRNA-1010 vaccine with coverage for one A/H3N2 strain. mRNA-1011.1 contains 5 mRNAs 
encoding HAs for A/H1N1, B/Victoria, B/Yamagata, and two A/H3N2 strains, while 
mRNA-1011.2 contains 4 mRNAs encoding HAs similar to mRNA-1011.1 (including coverage 
for two A/H3N2 strains) but with B/Yamagata excluded. The rationale for excluding 
B/Yamagata is due to the lack of circulation of B/Yamagata-lineage viruses in recent years and 
thus, allowing for a higher proportion of other strains to be represented in the vaccine within the 
same total mRNA dose. mRNA-1012.1 contains 5 mRNAs encoding HAs similar to 1011.2 but 
with 1 additional HA from the A/H3N2 lineages (coverage for three A/H3N2 strains). 
The comparator mRNA-1010 vaccine is the Sponsor’s first-generation quadrivalent vaccine 
containing HAs from A/H1N1, B/Yamagata, B/Victoria, and 1 of three A/H3N2 lineages that 
matches those in the next-generation vaccines (mRNA-1010, mRNA-1010.2, and 
mRNA‑1010.3). The mRNA-1010 vaccine is currently under investigation in an ongoing Phase 3 
immunogenicity study in adults ≥18 years of age (NCT05415462) and Phase 3 efficacy study in 
adults ≥50 years of age (NCT05566639). 
The objective of this study (mRNA-1011-P101) is to establish preliminary safety and 
immunogenicity data to support selection of a lead candidate for initiation of pivotal studies. The 
rationale for excluding B/Yamagata from mRNA-1011.2 and mRNA-1012.1 is due to limited 
circulation of B/Yamagata-lineage viruses in recent years and thus, allowing for a lower total 
mRNA dose or other strains to be represented in the vaccine within the same total mRNA dose. 
The mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1 and mRNA-1010 (mRNA-1010, 
mRNA-1010.2, and mRNA-1010.3) development candidates are administered as a single dose 
and are aimed to elicit protection from all seasonal influenza viruses covered by the candidate 
vaccines. 

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The study design has safety and reactogenicity evaluation as the primary objective, and with 
secondary objective of evaluating immunogenicity of each HA component using the HAI assay 
because HAI titers have been established as a correlate of protection against influenza illness. 
The rationale for this approach is based on the established precedent of using HA-based 
immunologic correlates for clinical assessment and licensure of influenza vaccines 
(DHHS 2007a; EMA 2016; Dunning et al 2016). 
2.2. 
Background and Overview 
Seasonal influenza viruses are estimated by the 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 NH and 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 monitoring network coordinated by the WHO (Monto 2018). 
Based on the observed circulation patterns and antigenic changes, the WHO expert panel 
recommends influenza virus strains to be used for vaccine manufacturing twice a year (once for 
the NH and SH independently). Influenza A and influenza B virus strains 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). 
The candidate vaccines to be evaluated are included in Section 4.1. 
Currently licensed seasonal influenza virus vaccines have suboptimal efficacy; rarely exceed 
50% overall effectiveness and are poorly effective during years when the circulating viruses do 
not match the strains selected for the vaccine antigens (CDC 2020). Influenza vaccines based on 
mRNA technology could provide several benefits compared to current vaccines, including the 
ability to respond to strain changes within a season more quickly, avoidance of mutations that 
may be acquired during traditional vaccine production in eggs or cell culture, potential for 
stronger immune responses, as well as improved protection in older adults (Rockman et al 2020).  
Current quadrivalent seasonal influenza vaccines are manufactured to prevent influenza illness 
caused by 4 influenza strains that include 2 influenza A strains (A/H1N1 and A/H3N2) and 2 
influenza B strains (B/Yamagata and B/Victoria). However, influenza A/H3N2 remains the 
major driver of influenza-related hospitalizations and deaths, particularly in older adults. Lower 
vaccine effectiveness against the influenza A/H3N2 viruses may be in part caused by vaccine 
mismatches that can occur due to co-circulation of multiple different A/H3N2 clades, whereas 
only one of those clades is generally covered by the vaccine. The inclusion of additional strains 
could allow for expanded coverage against multiple co-circulating A/H3N2 strains of distinct 
antigenic clades in influenza vaccination programs; and furthermore, enable public health 
authorities to recommend a higher number of strains for inclusion into the vaccine. 
The Sponsor is planning to test 3 next-generation influenza development candidates 
(mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1) containing additional influenza A/HA 
strains in a Phase 1/2 study to identify the optimal candidate to advance into pivotal studies. The 
Sponsor’s first-generation quadrivalent development candidate, mRNA-1010, which is based on 
WHO recommended influenza strains with different H3N2 HA in each, will be included as 
controls. The vaccines will be administered as a single dose with primary endpoints of safety and 

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reactogenicity with up to 6 months follow-up. Secondary endpoints will include assessing 
humoral protective immunity from influenza viruses covered by the vaccine. 
Lipid Nanoparticle-Encapsulated mRNA Development Program 
The Sponsor has developed a rapid-response, custom-manufactured vaccine platform based on a 
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. This platform is the basis of the Sponsor’s product, 
mRNA-1273 (SPIKEVAX®), that was granted approval for full licensure for active 
immunization to prevent COVID-19 infection in individuals 18 years of age and older. This 
same platform will be used for these proposed influenza mRNA vaccine candidates. 
2.2.1. 
Nonclinical Studies 
In support of the proposed Phase 1 clinical study of mRNA-1011.1, mRNA-1011.2, and 
mRNA-1012.1, nonclinical pharmacology, pharmacokinetic, and toxicology studies have been 
completed with the candidate vaccines or other similar mRNA-based vaccines formulated in the 
same LNPs containing SM-102. This includes mRNA-1010 and/or other mRNA vaccines that 
encode various antigens developed with the Sponsor’s mRNA-based platform using 
SM‑102‑containing LNPs. 
Data from the following nonclinical testing programs support the clinical development of 
mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1: 
• In BALB/c mice, mRNA-1011s and mRNA-1012 induced robust IgG-binding 
antibodies against each HA encoded by the vaccine, as well as robust HAI antibody 
titers. 
• In ferrets, mRNA-1011s and mRNA-1012 induced robust HAI antibody titers against 
each strain encoded by the vaccine. 
• The safety and tolerability of similar mRNA-based vaccines formulated in an 
SM-102-containing LNP matrix encapsulating mRNA constructs that encode for 
various antigens have been evaluated in multiple GLP-compliant, repeat-dose toxicity 
studies in Sprague Dawley rats, followed by a 2-week recovery period. The Sponsor 
proposes that the toxicity associated with mRNA vaccines formulated in LNP 
formulations is driven primarily by the LNP composition and, to a lesser extent, the 
biological activity of the expressed antigens of the mRNA vaccine. This is supported 
by the consistency of the aggregate rat repeat-dose toxicity profile observed in these 
GLP studies at IM doses ranging from 9 to 150 µg/dose administered once every 
2 weeks for up to 6 weeks and thus, is considered to be representative of mRNA 
vaccines formulated in the same SM-102 LNP matrix regardless of the encapsulated 
mRNA sequence(s). Thus, the aggregate toxicity results from these studies support 
the development of mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1. 
• In mouse and ferret pharmacology studies, the absence of synergistic or additive 
immune responses to the individual antigens in the mRNA-1011s and mRNA-1012 
immunogenicity studies suggests no synergistic or additive toxicities of various 

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antigens compared to mRNA-1010. mRNA-1010 has already been tested 
independently in nonclinical immunogenicity studies with safety endpoints, as well as 
human studies. Thus, additional repeat-dose toxicity studies with mRNA-1011.1, 
mRNA-1011.2, and mRNA-1012.1 were not conducted because they were not 
expected to contribute to the nonclinical risk assessment or identify new target organs 
of toxicities for mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1. 
• The biodistribution of mRNA-based vaccines formulated in LNPs is consistent with 
administration of other IM vaccines and distribution via the lymphatic system. mRNA 
does not persist past 1 to 3 days in tissues other than the muscle of the injection site, 
proximal popliteal and distal axillary lymph nodes, and spleen. The average half-life 
values range from 14.9 to 63.0 hours. 
• In vitro and in vivo studies have demonstrated that SM-102 is efficiently and 
extensively metabolized through ubiquitous and high capacity hydrolytic and 
oxidative pathways with no human-specific metabolites. Additionally, SM-102 and 
its metabolites are eliminated through both renal and hepatic routes (unpublished 
data). 
Details of mRNA-1010 are provided in the mRNA-1010 IB. 
2.2.2. 
Clinical Studies 
The Sponsor’s mRNA-1010-P101 study (NCT04956575) was a Phase 1/2, randomized, 
observer-blind, dose ranging study to evaluate the safety, reactogenicity, and immunogenicity of 
the mRNA-1010 vaccine in adult participants ≥18 years of age. The study comprised 3 parts: 
Phase 1/2 (placebo-controlled), Phase 2 NH (active-controlled), and Phase 2 Extension 
(active-controlled). All participants completed their 6-month follow-up.  
In the Phase 1/2 part, approximately 180 participants were randomly assigned in a 1:1:1:1 ratio 
to receive a single dose of mRNA-1010 at different dose levels (50, 100, or 200 µg of total 
mRNA) or placebo. The Phase 2 NH part randomized approximately 500 participants in a 
3:3:3:1 ratio to 1 of 4 vaccination groups to receive a single dose of mRNA-1010 at different 
dose levels (25, 50, or 100 µg of total mRNA) or a single dose of a licensed quadrivalent 
seasonal influenza vaccine (active comparator, Afluria®). The Phase 2 Extension part had 
randomized 200 participants in a 1:1:1:1 ratio to 1 of 4 vaccination groups to receive a single 
dose of mRNA-1010 at different dose levels (6.25, 12.5, or 25 µg of total mRNA) or a single 
dose of a licensed quadrivalent seasonal influenza vaccine (active comparator, Afluria). 
The mRNA-1010 vaccine included mRNAs that encoded for the HAs of the influenza virus 
strains recommended by the WHO for 2021 SH (Phase 1/2 part) and 2021-2022 NH (Phase 2 NH 
part and Phase 2 Extension part) cell- or recombinant-based vaccines. 
The Day 29 safety and immunogenicity interim analysis data are available from all 3 parts. 
Overall, no significant safety concerns have been observed across all doses from 6.25 to 200 µg. 
The local and systemic ARs were mostly mild to moderate in severity. The frequency and 
severity of solicited ARs in the mRNA-1010 groups increased in a dose-dependent manner. The 
younger age group (18 to <50 years old) had higher solicited ARs than the older adults 
(≥50 years old). The solicited ARs were higher in the mRNA-1010 groups than in the Afluria 
group. There were no Grade 4 ARs. There were no SAEs assessed by the Investigator as related 

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to the study intervention. There were no study discontinuations due to AEs, and no AEs that led 
to a study pause. 
Vaccination with mRNA-1010 elicited HAI antibodies in both younger and older adults against 
all strains at all dose levels. The HAI antibodies on Day 29 substantially exceeded 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. 
The 50-µg dose level of mRNA-1010 has been selected for further evaluation in the Phase 3 
studies based on this dose eliciting strong HAI antibody responses and demonstrating an 
acceptable reactogenicity and safety profile. The mRNA-1010 vaccine is currently being further 
evaluated in 2 additional clinical studies in adults: a Phase 3 safety and immunogenicity study in 
adults ≥18 years of age (Study mRNA-1010-P301, NCT05415462), and a Phase 3 safety and 
efficacy study in adults ≥50 years of age (mRNA-1010-P302, NCT05566639). 
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 
Participants will have a baseline (Day 1) evaluation for viral respiratory pathogens for protocol-
defined ILI throughout the study. 
The study will contribute to the development of a potentially efficacious vaccine against seasonal 
influenza. 
2.3.2. 
Risks from Study Participation and Their Mitigation 
Immediate systemic allergic reactions, ranging from mild (eg, urticaria) to severe (eg, 
anaphylaxis) may occur very rarely following any vaccination. Systemic allergic reactions 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 Sponsor’s mRNA-1273 
vaccine for COVID-19, the US 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 precaution, all participants will remain under observation at the 
study site for at least 60 minutes after injection. 
Vasovagal syncope (fainting) can occur before or after any vaccination, is usually triggered by 
pain or anxiety associated with the injection and is not related to the substance injected. 
Therefore, standard precautions and procedures will be followed to avoid injury from fainting. 
IM injection with other mRNA vaccines manufactured by the Sponsor containing the 
custom‑manufactured SM-102 ionizable 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 

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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. 
The most commonly reported local solicited ARs at the time of interim safety analysis in the 
ongoing Phase 1/2 mRNA-1010-P101 study were injection site pain and axillary swelling or 
tenderness. The most common systemic solicited ARs were headache, fatigue, myalgia, and 
chills. Most of these reactions were Grade 1 or 2 in severity and resolved within a few days. 
There have been 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). 
2.3.3. 
Overall Benefit/Risk Conclusion 
These vaccines may or may not offer protection against seasonal influenza. 
Considering the nonclinical data for mRNA-1011.1, mRNA 1011.2, and mRNA-1012.1, as well 
as the safety data for mRNA-1010 and other mRNA vaccines containing the 
custom‑manufactured SM-102 ionizable lipid formulation (eg, mRNA-1273) to date, the Sponsor 
considers the potential benefits of participation to exceed the risks. Refer to Section 2.2 for more 
details. 

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3. 
OBJECTIVES AND ENDPOINTS 
The study objectives and associated endpoints are provided in Table 2. 
Table 2: 
Study Objectives and Endpoints 
Objectives 
Endpoints 
Primary 
• 
To evaluate the safety and reactogenicity 
of mRNA-1011.1, mRNA-1011.2, 
mRNA-1012.1, and mRNA-1010 
controls (mRNA-1010, mRNA-1010.2 
and mRNA-1010.3) 
• 
Solicited local and systemic ARs through 7 days 
after injection 
• 
Unsolicited AEs through 28 days after injection 
• 
MAAEs from Day 1 to Day 181/EoS 
• 
AESIs from Day 1 to Day 181/EoS 
• 
SAEs from Day 1 to Day 181/EoS 
• 
AEs leading to discontinuation from Day 1 to 
Day 181/EoS 
Secondary 
• 
To evaluate the humoral immunogenicity 
of mRNA-1011.1, mRNA-1011.2, 
mRNA-1012.1 in comparison with 
mRNA-1010 controls (mRNA-1010, 
mRNA-1010.2, and mRNA-1010.3) 
against vaccine-matched influenza A and 
B strains at Day 29 
• 
GMT and GMFR, comparing Day 29 with Day 1 
(baseline), and percentage of participants with 
seroconversion, defined as a postbaseline titer 
≥1:40 if baseline is <1:10 or a 4-fold or greater rise 
if baseline is ≥1:10 in anti-HA antibodies measured 
by HAI assay 
Exploratory (may be performed) 
• 
To evaluate the humoral immunogenicity 
of mRNA-1011.1, mRNA-1011.2, 
mRNA-1012.1, and mRNA-1010 
controls against vaccine-matched 
influenza A and B strains at all evaluable 
humoral immunogenicity timepoints 
• 
GMT, GMTR (mRNA-1011.1, mRNA-1011.2, and 
mRNA-1012.1 against mRNA-1010), and GMFR 
(compared with Day 1) of anti-HA as measured by 
HAI assay 
• 
To evaluate the humoral immunogenicity 
against vaccine-matched influenza A and 
B strains by alternative methods at all 
evaluable timepoints 
• 
GMT and GMFR (compared with Day 1) of 
anti‑HA antibodies as measured by MN assays or 
other alternative methods against vaccine matched 
strains 
• 
To evaluate the humoral immunogenicity 
against vaccine-mismatched influenza A 
and B strains at all evaluable timepoints 
• 
GMT and GMFR (compared with Day 1) of 
anti‑HA antibodies as measured by HAI or MN 
assays against vaccine-mismatched strains 
• 
To evaluate cellular immunogenicity in a 
subset of participants at all evaluable 
timepoints 
• 
Frequency, magnitude, and phenotype of 
virus‑specific B-cell responses measured by flow 
cytometry or other methods, and to perform 

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Objectives 
Endpoints 
targeted repertoire analysis of B-cells after 
vaccination 
• 
To assess the occurrence of clinical 
influenza in study participants and 
characterize their immune response to 
infection and viral isolates 
• 
Frequency of RT-PCR-confirmed ILI and 
assessment of immune responses in participants 
with RT-PCR–confirmed ILI 
Abbreviations: AE = adverse event; AESI = adverse event of special interest; EoS = end of study; GMFR = 
geometric mean fold rise; GMT = geometric mean titer; HA = hemagglutinin; ILI = Influenza-like illness; 
GMTR = geometric mean titer ratios; HAI = hemagglutination inhibition; MAAE = medically attended adverse 
event; MN = microneutralization; mRNA = messenger ribonucleic acid; RT-PCR = reverse transcription 
polymerase chain reaction; SAE = serious adverse event. 

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4. 
STUDY DESIGN 
4.1. 
General Design 
This prospective, open-label Phase 1/2 study will enroll approximately 700 healthy adults 
≥50 to ≤75 years of age. 
On Day 1, each participant will be randomized to receive a single injection administered 
intramuscularly in the deltoid muscle and followed for 6 months.  
The candidate vaccines to be evaluated include: 
• mRNA-1011.1 vaccine consisting of 5 mRNAs encoding the HA surface 
glycoproteins of 4 influenza strains (A/H1N1, A/H3N2, B/Victoria lineage, and 
B/Yamagata lineage) recommended by the WHO for the 2022/2023 NH season, and 1 
additional A/H3N2 influenza strain (A/Newcastle/1/2021). 
• mRNA-1011.2 vaccine consisting of 4 mRNAs encoding the HA surface 
glycoproteins of 3 influenza strains (A/H1N1, A/H3N2, and B/Victoria lineage) 
recommended by the WHO for the 2022/2023 NH season, and 1 alternative A/H3N2 
influenza strain (A/Newcastle/1/2021) to replace B/Yamagata. 
• mRNA-1012.1 vaccine consisting of 5 mRNAs encoding the HA surface 
glycoproteins of 3 influenza strains (A/H1N1, A/H3N2, and B/Victoria lineage) 
recommended by the WHO for the 2022/2023 NH season, and 2 additional A/H3N2 
influenza strains (A/Newcastle/1/2021 and A/Hong Kong/45/2019) to replace 
B/Yamagata.  
• mRNA-1010: mRNA-1010 (Darwin) vaccine consisting of 4 mRNAs encoding the 
HA surface glycoproteins of 4 influenza strains (A/H1N1, A/H3N2, B/Victoria 
lineage, and B/Yamagata lineage) recommended by the WHO for the 2022/2023 NH 
season. 
• mRNA-1010.2: mRNA-1010 (Newcastle) vaccine consisting of 4 mRNAs encoding 
the HA surface glycoproteins of 3 influenza strains (A/H1N1, B/Victoria lineage, and 
B/Yamagata lineage) recommended by the WHO for the 2022/2023 NH season, and 1 
alternative A/H3N2 influenza strain (A/Newcastle/1/2021). 
• mRNA-1010.3: mRNA-1010 (Hong Kong) vaccine consisting of 4 mRNAs encoding 
the HA surface glycoproteins of 3 influenza strains (A/H1N1, B/Victoria lineage, and 
B/Yamagata lineage) recommended by the WHO for the 2022/2023 NH season, and 1 
alternative A/H3N2 influenza strain (A/Hong Kong/45/2019). 
Participants will be stratified by prior season influenza vaccination status; those who received a 
licensed or investigational influenza vaccine within 180 days prior to enrollment will be 
excluded. A complete listing of inclusion and exclusion criteria is provided in Section 5.1 and 
Section 5.2, respectively. 
Different dose levels will be assessed in parallel across 7 treatment arms with the number of 
participants and groups as detailed in Table 3. Data on all 3 investigational mRNA-1011/1012 
influenza candidates compared to mRNA-1010 controls will be collected simultaneously. 

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Study visits will consist of a Screening Visit (up to 28 days before the Day 1 visit), 
Randomization Visit at Day 1 (Baseline), and subsequent study visits on Day 8, Day 29 
(Month 1), and Day 181/(EoS; Month 6), with up to 7 months of study participation. 
Unscheduled visits for potential ILI symptoms will include testing with a multiplex respiratory 
infection panel (BioFire or similar). 
In addition, there will be 5 safety telephone call visits at Days 15, 57, 91, 121, and 151 as 
specified in the SoE (Table 1). All participants will be asked to complete an eDiary for solicited 
ARs from Day 1 to Day 7. 
Table 3: 
Study Arms and Dose Levels 
Vaccination 
Group 
Group Name 
Composition 
Total 
Dose 
N 
(total) 
1 
mRNA-1011.1 
A/H1N1, B/Yamagata, B/Victoria, 
A/H3N2 (Darwin), A/H3N2 (Newcastle) 
at 1:1:1:1:1 
50 µg 
100 
2 
mRNA-1011.2 
A/H1N1, B/Victoria, A/H3N2 (Darwin), 
A/H3N2 (Newcastle) at 1:1:1:1 
40 µg 
100 
3 
mRNA-1012.1 
A/H1N1, B/Victoria, A/H3N2 (Darwin), 
A/H3N2 (Newcastle), A/H3N2 (Hong 
Kong) at 1:1:1:1:1 
50 µg 
100 
4 
mRNA-1012.1 
A/H1N1, B/Victoria, A/H3N2 (Darwin), 
A/H3N2 (Newcastle), A/H3N2 (Hong 
Kong) at 1:1:1:1:1 
62.5 
µg 
100 
5 
mRNA-1010 
(Darwin)  
(Control) 
A/H1N1, B/Yamagata, B/Victoria, 
A/H3N2 (Darwin) at 1:1:1:1 
50 µg 
100 
6 
mRNA-1010.2 
(Newcastle) 
(Control) 
A/H1N1, B/Yamagata, B/Victoria, 
A/H3N2 (Newcastle) at 1:1:1:1 
50 µg 
100 
7 
mRNA-1010.3 
(Hong Kong) 
(Control) 
A/H1N1, B/Yamagata, B/Victoria, 
A/H3N2 (Hong Kong) at 1:1:1:1 
50 µg 
100 
Abbreviations: mRNA = messenger ribonucleic acid. 
4.2. 
Scientific Rationale for Study Design 
This study will enroll healthy adults aged ≥50 to ≤75 years to evaluate next-generation influenza 
mRNA vaccine candidates. This broad age range allows inclusion of older adults who often have 
higher risk of comorbidities and conditions that could lead to more negative health outcomes due 
to influenza. mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1 could provide a public health 
benefit through increasing protection against circulating influenza A/H3N2 strains. 
The additional H3N2 strains evaluated in this study were selected by the Sponsor for their 
antigenic distance compared to the Darwin strain contained in the 2022/2023 NH vaccine 
composition and greater antigenic breadth across the H3N2 virus family. Due to WHO reporting 

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limited circulation of the B/Yamagata virus in recent years, the mRNA-1011.1 and 
mRNA‑1012.1 candidates were designed to not contain the B/Yamagata HA, allowing for higher 
proportion of other strains/additional strains to be represented in the vaccine. Data from this 
study will help distinguish the immune responses against the respective vaccine strains, using the 
HAI assay, and evaluate the added benefit of mRNAs encoding additional influenza A/H3N2 
strains from the WHO recommended strains. The Sponsor expects to follow public health 
recommendations for inclusion of multiple H3N2 strains once such recommendations are 
available. 
The study will be conducted in an open-label manner. Since all study arms will receive DP in a 
relatively narrow dosage range that have the same clinical indication, developed with the same 
technology platform (mRNA platform) and there is no placebo arm, the preference or bias for 
particular study products would be perceived to be minimum from either investigators’ or 
participants’ perspective. 
4.3. 
Justification for Dose 
The selection of the 50-µg dose level of the Sponsor’s mRNA-1010 candidate is supported by 
the data from the Phase 1/2 and the Phase 2 NH interim analyses (see mRNA-1010 IB).  
The safety and immunogenicity profile observed from the mRNA-1010-P101 study supports the 
use of 50 µg total mRNA dose level as the dose to base a dose-ranging study of these 
next‑generation influenza mRNA candidates and in the selection of dosage of control 
comparisons. mRNA-1010 is a quadrivalent vaccine and contains 12.5 µg of mRNA encoding 
for each HA strain for a total of 50 µg mRNA, the dose of all the mRNA-1010 controls. 
The mRNA-1011.1 and mRNA 1011.2 each contain 10 µg of each HA strain, resulting in a 
50 µg and 40 µg dosage in the pentavalent and quadrivalent vaccine, respectively. 
mRNA‑1012.1 is also a pentavalent vaccine and has a total dose of 50 µg with 10 µg of each 
HA. Lastly, mRNA-1012.1 will also be tested at a 62.5 µg dose, with 12.5 µg of each HA strain 
similar to the mRNA-1010 controls, thereby allowing evaluation of reactogenicity of each HA 
strain at the same dosage. 
4.4. 
End of Study Definition 
A participant is considered to have completed the study if he or she has completed all periods of 
the study (Table 1). The end of study is defined as completion of the last visit of the last 
participant in the study or last scheduled procedure(s) as shown in the SoE (Table 1). 

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5. 
STUDY POPULATION 
Prospective approval of protocol deviations to recruitment and enrollment criteria, also known as 
protocol waivers or exemptions, is not permitted. 
5.1. 
Inclusion Criteria 
Each participant must meet all of the following criteria to be enrolled in this study: 
1. Adults ≥50 to ≤75 years of age at the time of consent (Screening Visit) who, in the 
opinion of the Investigator, are in good health based on review of medical history and 
physical examination performed at the Screening Visit. 
2. Investigator assessment that participant understands and is willing and physically able 
to comply with protocol-mandated follow-up and procedures. 
3. Able to provide written informed consent for participation in this study, including all 
evaluations and procedures as specified in this protocol. 
4. Body mass index of 18 kg/m2 to 35 kg/m2 (inclusive) at the Screening Visit. 
5. Women of nonchildbearing potential may be enrolled in the study. Nonchildbearing 
potential is defined as postmenopausal or permanently sterilized. FSH level may be 
measured at the discretion of the Investigator to confirm postmenopausal status. 
6. Women 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 
(Day 1). 
− Has practiced adequate contraception or has abstained from all activities that 
could result in pregnancy for at least 28 days prior to Day 1. Adequate female 
contraception is defined as consistent and correct use of a locally authorized or 
approved contraceptive method in accordance with the product label. 
− Has agreed to continue adequate contraception through 3 months following 
vaccine administration. 
− Is not currently breastfeeding. 
5.2. 
Exclusion Criteria 
Participants meeting any of the following criteria will be excluded from the study: 
1. 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. 
2. Clinical screening laboratory values for total white blood cell count, hemoglobin, 
alanine aminotransferase, aspartate aminotransferase, creatinine, alkaline 
phosphatase, and total bilirubin are >Grade 1 or platelets ≥Grade 1. 

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3. 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.  
− Asymptomatic conditions and conditions with no clinically significant end-organ 
involvement (eg, mild hypertension, dyslipidemia) are not exclusionary, provided that 
the participant is being appropriately managed and are clinically stable (ie, unlikely to 
result in symptomatic illness within the time course of this study). Illnesses or 
conditions may be exclusionary, even if otherwise stable, due to therapies used to treat 
them (eg, immunosuppressive treatments), at the discretion of the Investigator. 
− Participants who have undergone surgical procedures within 28 days prior to 
Day 1 or are scheduled to undergo a surgical procedure within 28 days after study 
intervention administration are excluded. Minor surgical procedures under local 
anesthesia (eg, excision of skin lesion) or screening and diagnostic procedures 
(eg, colonoscopy) are allowed. 
4. 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: 
− Certain immune-mediated conditions that are stable and well controlled (eg, 
Hashimoto thyroiditis), as well as those that do not require systemic 
immunosuppressants (eg, asthma, psoriasis, or vitiligo) may be permitted at the 
discretion of the Investigator. 
5. Dermatologic conditions that could affect local solicited AR assessments (eg, tattoos, 
psoriatic patches or vitiligo affecting skin over the deltoid injection site area). 
6. History of anaphylaxis or severe hypersensitivity reaction requiring medical intervention 
after receipt of a vaccine or any of the components contained in mRNA vaccines. 
7. Coagulopathy or a bleeding disorder that is considered a contraindication to IM 
injection or phlebotomy. 
8. Diagnosis of malignancy within previous 5 years (excluding non-melanoma skin cancer). 
9. Any medical, psychiatric, or occupational condition, including reported history of 
substance abuse, that in the opinion of the Investigator might pose additional risk due 
to participation in the study or could interfere with the interpretation of study results. 
10. Has received systemic immunosuppressants for >14 days in total within 180 days 
prior to the Randomization 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 (including intra-articular steroid 
injections). Inhaled, nasal, and topical steroids are allowed. 
11. Has received or plans to receive any licensed or authorized vaccine, including 
COVID-19 vaccines, ≤28 days prior to the study injection (Day 1) or plans to receive 
a licensed or authorized vaccine within 28 days after the study injection. 
12. Has received a seasonal influenza vaccine or any other investigational influenza 
vaccine within 180 days prior to the Randomization Visit. 

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13. Has tested positive for influenza by local health authority-approved testing methods 
within 180 days prior to the Randomization Visit. 
14. Has been treated with antiviral therapies for influenza (eg, Tamiflu®) within 180 days 
prior to the Randomization Visit. 
15. Has had 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 Randomization Visit. 
16. Has had close contact to someone or been diagnosed themselves with respiratory 
syncytial virus or SARS‑CoV-2 infection as defined by the CDC in the past 10 days 
prior to the Randomization Visit. 
17. Has received systemic immunoglobulins, long-acting biological therapies that affect 
immune responses (eg, infliximab), or blood products within 90 days prior to the 
Randomization Visit or plans to receive them during the study. 
18. History of myocarditis, pericarditis, or myopericarditis. 
19. History of Guillain-Barre syndrome. 
20. Has donated ≥450 mL of blood products within 28 days prior to the Randomization 
Visit or plans to donate blood products during the study. 
21. Has participated in an interventional clinical study within 28 days prior to the 
Randomization Visit or plans to do so while participating in this study. Participants 
may continue in prior interventional study follow-up activities, as long as it does not 
involve further investigational treatment other than described in this protocol. (Note: 
Interventions such as counseling, biofeedback, and cognitive therapy are not 
exclusionary). 
22. Is working or has worked as a study personnel or is an immediate family member or 
house 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 should defer vaccination with licensed or authorized vaccines, including 
COVID-19 vaccines, until after completion of their Day 29 Visit. 
5.4. 
Screen Failures 
Screen failures are defined as participants who consent to participate in the clinical study but are 
not subsequently randomly assigned to treatment. A minimum set of screen failure information is 
required to ensure transparent reporting of screen failures to meet the Consolidated Standards of 
Reporting Trials publishing requirements and to respond to queries from regulatory authorities. 
Minimum information includes date of informed consent, demography, reason(s) for screen 
failure, and eligibility criteria. 

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6. 
STUDY INTERVENTIONS 
6.1. 
Study Interventions Administered 
The term “study intervention” refers to mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1, and 
mRNA-1010 controls (mRNA-1010, mRNA-1010.2 and mRNA-1010.3) that will be 
administered in this study. The vaccines to be evaluated are described in Section 4.1. 
All mRNAs are formulated in LNPs composed of 4 lipids and provided as a sterile liquid for 
injection, white-to-off white dispersion in appearance.  
6.2. 
Randomization 
Randomization will be performed using an IRT system. 
The Sponsor’s Biostatistics Department or designee will generate the randomized allocation 
schedule(s) for vaccination group assignment. Overall, approximately 700 healthy adults will be 
randomized in parallel into 7 treatment arms to receive either mRNA-1011.1, mRNA-1011.2, 
and mRNA-1012.1 candidate seasonal influenza vaccines or mRNA-1010 control (mRNA-1010, 
mRNA-1010.2, and mRNA-1010.3) vaccines, with approximately 100 healthy adult participants 
randomly assigned to each of vaccination groups 1 to 7. Different dose levels will be assessed in 
parallel (Table 3). Randomization will be stratified by influenza vaccination status in the 
previous influenza season (received or not received). 
6.3. 
Preparation/Handling/Storage/Accountability 
6.3.1. 
Preparation of Study Intervention 
The study intervention will be prepared for each participant based on the vaccination group. The 
study intervention (mRNA-1011.1, mRNA-1011.2, mRNA-1012.1, and mRNA-1010 controls) 
preparation instructions are detailed in the Pharmacy Manual. 
6.3.2. 
Study Intervention Administration 
The study intervention (mRNA-1011.1, mRNA-1011.2, mRNA-1012.1, and mRNA-1010 
controls) will have a dose volume of 0.5 mL and will be administered as a single IM injection 
into the deltoid muscle on Day 1, with preference in the non-dominant arm. 
Participants will be monitored for a minimum of 60 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 study site 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-1011.1, mRNA-1011.2, 
mRNA-1012.1, and mRNA-1010 controls are described in the Pharmacy Manual. 

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6.3.3. 
Study Intervention Delivery and Receipt 
The Sponsor or designee is responsible for the following: 
• Supplying the study interventions; mRNA-1011.1, mRNA-1011.2, mRNA-1012.1, 
and mRNA-1010 controls. 
• Confirming the appropriate labeling of the study intervention for clinical study use so 
that it complies with the US legal requirements. 
The Investigator is responsible for acknowledging receipt of the study intervention by a 
designated staff member at the site, which includes the following: 
• Confirming that the study intervention was received in good condition. 
• Confirming that the temperature during shipment from the Sponsor to the 
Investigator’s designated storage location was appropriate. 
• Confirming that the Sponsor has authorized the study intervention for use. 
• Ensuring the appropriate dose level of the study intervention is properly prepared 
using aseptic technique. 
Further description of the study intervention and corresponding instructions for the receipt, 
storage, preparation, administration, accountability, and destruction are described in the 
Pharmacy Manual. 
6.3.4. 
Study Intervention Packaging and Labeling 
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 of its designee, CFR Title 21 GMP 
guidelines, ICH GCP guidelines, guidelines for Quality System Regulations, and applicable 
regulations. 
6.3.5. 
Study Intervention Storage 
All study interventions must be stored in a secure area with limited access and must be protected 
from moisture and light until it is prepared for administration in accordance with the instructions 
in the Pharmacy Manual. 
6.3.6. 
Study Intervention 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. 

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6.3.7. 
Study Intervention Handling and Disposal 
A site monitor will reconcile the study intervention during study conduct and at the end of the 
study for compliance. Once fully reconciled at the site, the study intervention can be destroyed at 
the investigational site or a Sponsor selected third party, as appropriate. 
Study intervention may be destroyed at the study site only if permitted by local regulations and 
authorized by the Sponsor. A document for destruction (ie, Certificate of Destruction) must be 
obtained and sent to the Sponsor or designee. Refer to Pharmacy Manual for further directions. 
6.4. 
Study Intervention Compliance 
All study interventions will be administered at the study site under direct observation of 
medically qualified study staff, and study intervention administration will be appropriately 
recorded (date and time) in the eCRF. Qualified staff will confirm that the participant has 
received the entire dose of the study intervention. If a participant does not receive the study 
intervention, the reason for the missed dose will be recorded. Data will be reconciled with site 
accountability records to assess compliance. 
The study site staff are responsible for ensuring that participants comply with the allowed study 
visit windows. If a participant misses a visit, every effort should be made to contact the 
participant and complete a visit within the defined visit window specified in the SoE (Table 1). If 
a participant does not complete a visit within the time window, that visit will be classified as a 
missed visit and the participant will continue with subsequent scheduled study visits. All safety 
requirements of the missed visit will be captured and included in the subsequent visit. 
6.5. 
Dose Modification 
No dose modifications are allowed. 
6.6. 
Continued Access to Study Intervention after the End of the Study 
There will be no access to study intervention following the end of the study. 
6.7. 
Prior and Concomitant Therapy 
At each visit, the study site staff should question the participant regarding any medications taken 
and vaccinations received and record the information as specified in Section 6.7.1 and 
Section 6.7.2. 
6.7.1. 
Prior Medications and Therapies 
Information about prior medications (including any prescription or over-the-counter medications, 
vaccines, or blood products) taken by the participant within the 28 days before providing 
informed consent (or as designated in the inclusion/exclusion requirements) will be recorded in 
the eCRF. 
6.7.2. 
Concomitant Medications and Vaccinations 
The following information regarding concomitant medication and vaccinations will be recorded 
in the eCRF: 

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• All nonstudy vaccinations administered within the period starting 28 days before the 
study intervention and through Day 181 (Month 6)/EoS. 
• Any authorized or investigational COVID-19 vaccine at any time before the study 
intervention and through Day 181 (Month 6)/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. 
• Systemic steroids (≥10 mg/day of prednisone or equivalent), immunosuppressants, 
immunoglobulins, or long-acting biological therapies that affect immune responses 
(eg, infliximab), 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 a SAE, AESI, or 
MAAE from Day 1 through Day 181 (Month 6)/EoS. 
• The participant will be asked in the eDiary if they have taken any antipyretic or 
analgesic medication 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 study site staff during 
the study visits after vaccination or via other participant interactions (eg, telephone 
calls). 
Concomitant medications (including vaccinations) will be coded using the WHODrug Global 
Dictionary. 
It is the Investigator’s responsibility to ensure that details regarding the concomitant medications 
are adequately recorded in the eCRF. 
6.7.3. 
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 PP analysis 
(Analysis sets are described in Section 9.4.): 
• Any investigational or non-registered product (drug or vaccine) other than the study 
intervention used during the study period. 
• Immunosuppressants administered chronically (more than 14 days in total) during the 
study period. For corticosteroids, ≥10 mg/day of prednisone or equivalent is not 
permitted. Inhaled, nasal, and topical steroids are allowed. 
• An authorized or licensed vaccine administered within 28 days after the study 
vaccination. 
• Immunoglobulins or long-acting biological therapies that affect immune responses 
(eg, infliximab) or any blood products administered during the study period. 

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7. 
DELAY OR DISCONTINUATION OF STUDY INTERVENTION 
AND PARTICIPANT DISCONTINUATION/WITHDRAWAL 
7.1. 
Pause Rules 
Study pause rules will be continuously monitored during the study by the Investigators and IST, 
as warranted. If the Investigator and/or IST request that the study be paused due to a safety 
concern, further study intervention will be suspended while all other planned procedures relating 
to safety, reactogenicity, and immunogenicity assessments will continue as described in the 
protocol. The Sponsor will notify the Center for Biologics Evaluation and Research within 
48 hours in the event of a study pause. 
7.1.1. 
Pause Rules Based on the Occurrence of a Single Event and Adjudicated by the 
Data Safety Monitoring Board 
The occurrence of any of the events listed in Table 4, regardless of the treatment arm, will result 
in immediate pause of enrollment. An unscheduled safety review will be convened to assess 
specific data concerns and make recommendations. 
Table 4: 
Pause Rule Criteria, Events, and Thresholds - Single Event 
Pause 
Rule 
Event 
Number of 
Participants 
1 
Any SAE that cannot be reasonably attributed to a cause other than 
study vaccination 
≥1 
2 
Any Grade 4 local or systemic solicited AR or any Grade 4 laboratory 
abnormality that cannot be reasonably attributed to a cause other than 
study vaccinationa 
≥1 
3 
Any case of myocarditis and/or pericarditis that cannot be reasonably 
attributed to a cause other than study vaccination 
≥1 
Abbreviations: AE = adverse event; AR = adverse reaction; FDA = Food and Drug Administration; SAE = serious 
adverse event; US = United States. 
a 
Grading of laboratory parameters will be based on the US FDA Guidance for Industry “Toxicity Grading Scale 
for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials.” (DHHS 2007b). 
 
7.1.1.1. 
Pause Rules Based on the Occurrence of Events in a Proportion of Participants 
The occurrence of safety events that will pause study dosing based on defined threshold levels, 
which are aggregate incidences relative to the number of exposed participants within a 
vaccination group, are summarized in Table 5. 

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Table 5: 
Pause Rule Criteria, Events, and Thresholds – Proportion of Participants 
Pause 
Rule 
Event 
Number or Percentage of 
Participantsa 
4 
Any severe unsolicited nonserious AE that cannot 
be reasonably attributed to a cause other than the 
study vaccination (independent of within or not 
within the same system organ class) 
≥2 participants per group or ≥20% of 
total participantsb 
5 
Any Grade 3 local solicited AR lasting more than 
48 hours that cannot be reasonably attributed to a 
cause other than the study vaccination, starting 
within the 7-day postdosing periodc 
≥2 participants per group or ≥20% of 
total participantsb 
6 
Any Grade 3 systemic solicited AR lasting more 
than 48 hours (24 hours for fever) that cannot be 
reasonably attributed to a cause other than the 
study vaccination, starting within the 7-day 
postdosing periodc 
≥2 participants per group or ≥20% of 
total participantsb 
Abbreviations: AE = adverse event; AR = adverse reaction; MedDRA = Medical Dictionary for Regulatory 
Activities. 
a 
The rate of AEs/ARs will be computed based on the number of exposed participants in each treatment group. 
For solicited ARs, participants need to experience the same solicited AR. Unsolicited events will be counted 
independent of within or not within the same system organ class. 
b 
For the first 7 participants in each dosing group, the pause rule will be considered met if two of the first 
7 participants experience AEs/ARs per footnote a. The calculation for ≥20% of participants includes the total 
number of participants within a dosing group who have completed a postdosing visit in the denominator. 
Reactogenicity e-diary data confirmed by the Investigator as being entered by the participant in error will not 
contribute toward a stopping rule.   
c 
Grading of parameters will be based on the US FDA Guidance for Industry “Toxicity Grading Scale for Healthy 
Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials.” (DHHS 2007b). 
 
If a pause is triggered in the study, each participant’s study site visits will continue until EoS. If a 
pause affects a participant’s vaccination visit, the window for that participant’s vaccination visit 
will be suspended until the pause is lifted and vaccination can resume. Once the pause is lifted, 
vaccination should be reinstated as soon as possible. 
If a participant is in the screening period for more than 28 days as a result of a pause, the 
participant may be rescreened for study eligibility (and will receive a new screening number) as 
long as the participant continues to provide consent to participate in the study. 
7.2. 
Criteria for Delay or Withholding of Study Intervention 
Body temperature must be measured at the dosing visit before administration of study 
intervention. The following events constitute criteria for delay of injection, and if any of these 
events occur at the time scheduled for dosing, the participant may be injected at a later date 
within the time window specified in the SoE (Table 1): 
• Acute moderate or severe infection with or without fever at the time of dosing. 
• Fever, defined as body temperature ≥38.0°C (100.4°F) at the time of dosing. 
• Receipt of all other vaccinations within 28 days of planned Day 1. 

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Participants with a minor illness in the absence of fever, as assessed by the Investigator, can be 
administered the study intervention. Participants with a fever ≥38.0°C (100.4°F) will be 
contacted within the time window acceptable for participation and reevaluated for eligibility. If 
the Investigator determines that the participant’s health on the day of administration temporarily 
precludes injection, the visit should be rescheduled within the allowed interval for that visit. 
The Investigator, in consultation with the Sponsor’s medical monitor, should withhold the study 
intervention if the participant meets any of the following criteria: 
• Becomes pregnant. 
• Develops symptoms or conditions listed in the exclusion criteria. 
• Experiences a clinically significant change in clinical laboratory test results, vital sign 
measurements or general condition that, in the judgment of the Investigator, requires 
withholding of study intervention. 
The reason(s) for withholding the study intervention will be recorded in the eCRF. 
If a participant takes a prohibited drug therapy, the Investigator could delay the study 
intervention within the visit window or withhold the study intervention based on a joint decision 
of the Investigator and the CRO’s medical monitor. 
7.3. 
Participant Discontinuation/Withdrawal from the Study 
Participants who withdraw or are withdrawn from the study will not be replaced unless otherwise 
stated in the protocol. 
A “withdrawal” from the study refers to a situation wherein a participant does not return for the 
final visit planned 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 the participant to 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 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 related 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 the reason for withdrawal. 
Participants who are withdrawn from the study because of AEs (including SAEs, solicited ARs, 
or reactogenicity events) 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, solicited AR, or reactogenicity event until resolution of the event. 
A participant withdrawing from the study 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 (Section 11.1.6). 
The Sponsor will continue to retain and use all research results that have already been collected 
for the study evaluation, unless the participant has requested destruction of these samples. All 
biological samples that have already been collected may be retained and analyzed at a later date 
(or as permitted by local regulations). 
7.4. 
Lost to Follow-up 
A participant will be considered LTFU if he or she 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 LTFU, the Investigator or designee must make every 
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 local 
equivalent methods). These contact attempts (eg, dates of telephone calls and 
registered letters) should be documented in the participant’s medical record. 
• A participant who continues to be unreachable or continues to be noncompliant with 
study visits or procedures 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 
Before performing any study procedures, all potential participants will sign an informed consent 
form (Section 11.1.6). Participants will undergo study procedures at the timepoints specified in 
the SoE (Table 1). 
A participant can also be seen for an unscheduled visit at any time during the study. Reasons for 
an unscheduled visit may include, but are not limited to, reactogenicity issues, symptoms of 
potential ILI, and new or ongoing AEs. The site also has discretion to make reminder telephone 
calls or send text messages to inform the participant about visits, review eDiary requirements, or 
follow-up on ongoing or outstanding issues. 
General considerations for study assessments and procedures include the following: 
• Protocol waivers or exemptions are not allowed. The study procedures and their 
timing must be followed as presented in the SoE (Table 1). Adherence to the study 
design requirements is essential and required for study conduct. 
• Immediate safety concerns should be discussed with the Sponsor immediately upon 
occurrence or awareness to determine if the participant should continue participation 
in the study. 
• All screening evaluations must be completed and reviewed to confirm that potential 
participants meet all eligibility criteria. The Investigator will maintain a screening log 
to record details of all participants screened and to confirm eligibility or record 
reasons for screening failure, as applicable. 
• The Screening Visit and Day 1 Visit will not be performed on the same day. The 
Screening Visit may be performed over multiple visits if within the 28-day screening 
window. 
8.1. 
Study Vaccine Administration 
A single dose vaccination (mRNA-1011.1, mRNA-1011.2, mRNA-1012.1, or mRNA-1010 
controls) 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. 
8.2. 
Safety Assessments and Procedures 
Safety assessments will include monitoring and recording of the following for each participant, 
according to the SoE (Table 1): 
• Solicited local and systemic ARs (Section 8.4.4) that occur during the 7 days 
following the study intervention (ie, the day of study vaccination [Day 1] and 6 
subsequent days). Solicited ARs will be recorded daily using eDiaries. 
• Unsolicited AEs observed or reported within 28 days following the study 
intervention, with the day of study vaccination as Day 1 (Section 8.4.2). 

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• AEs leading to discontinuation from study participation from Day 1 through Day 181 
(Month 6)/EoS or withdrawal from the study. 
• MAAEs from Day 1 through Day 181 (Month 6)/EoS or withdrawal from the study 
(Section 8.4.5). 
• AESIs from Day 1 through Day 181 (Month 6)/EoS or withdrawal from the study 
(Section 8.4.6). 
• SAEs from Day 1 through Day 181 (Month 6)/EoS or withdrawal from the study 
(Section 8.4.3). 
• Results of abnormal safety laboratory tests (Section 8.2.12). 
• Abnormal vital sign measurements (Section 8.2.1). 
• Abnormal physical examination findings (Section 8.2.1). 
• Details of all pregnancies in female participants will be collected from Day 1 through 
Day 181 (Month 6)/EoS (Section 8.2.2). 
8.2.1. 
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, pulse 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 study intervention and 
at least 60 minutes after study intervention administration, prior to discharge of the participant. 
On the day of Vaccination (Day 1), injection site and associated draining lymph nodes should be 
examined prior to administration of study intervention and results documented for any 
abnormalities. 
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. 
8.2.2. 
Pregnancy Testing 
A point-of-care urine pregnancy test will be performed for all female participants of childbearing 
potential at the Screening visit and before study intervention administration on Day 1. 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 

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Screening visit, at the discretion of the Investigator, when necessary, to confirm postmenopausal 
status (Contraceptive Guidance, Section 11.2). 
Further details on reporting and follow-up of pregnancy are provided in Section 8.2.6. 
8.2.3. 
Assessments for Respiratory Viral Infections 
NP swab specimen(s) for viral respiratory pathogens will be collected prior to study intervention 
administration on Day 1. Throughout the study, the participant will be instructed to contact the 
study site if he/she has symptoms suggestive of ILI. An unscheduled visit for symptom 
assessment and NP swab for viral respiratory pathogens will be conducted if a participant has 
protocol-defined ILI ≤7 days of symptom onset. 
8.2.4. 
Safety Telephone Calls 
A safety telephone call will be made to the participant by trained study site staff using a script to 
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 call 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. 
8.2.5. 
Use of Electronic Diaries 
At the time of consent, the participants must confirm they are 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 7. 
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 8.4.4. 
At the dosing visit, participants will record data into the eDiary starting approximately 60 
minutes after dosing under supervision of the study site staff to ensure successful entry of 
assessments. The 60-minute observation period is an opportunity for the study site staff to train 
the participant on eDiary completion requirements. The site staff will perform any retraining as 
necessary. 
At the dosing visit, participants will also 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) during the 7 days after study vaccination. Daily 
measurements should be performed at approximately the same time each day using the 
thermometer and ruler provided by the study 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 signs or 
symptoms of ILI. If eDiary questions result in identification of relevant safety events according 

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to the study period, a follow-up safety call will be triggered. The results of the safety call should 
be recorded in the appropriate source documentation. 
If a participant does not respond to the eDiary questions according to the SoE, study site staff 
will follow-up with the participant. 
8.2.6. 
Recording and Follow-up of Pregnancy 
The effects of the study interventions 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 181 (Month 6)/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. 
8.2.7. 
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 study vaccination and 6 subsequent days). Other (unsolicited) AEs will be collected from 
Day 1 through 28 days after the study intervention (ie, the day of study vaccination and 27 
subsequent days). 
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. Any AEs occurring before receipt of 
the study intervention will be analyzed separately from TEAEs. 

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At every study site visit or telephone contact, participants will be asked a standard set of 
questions to elicit any medically related changes in their well-being (including surveillance for 
respiratory viral infection symptoms) according to a provided script. 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 nonstudy vaccinations. 
In addition to participant observations, physical examination findings and other documents 
relevant to participant safety classified as an AE will be documented in EDC. 
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 7.4). 
8.2.8. 
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 in EDC. 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 of event, 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, stable or judged by the Investigator to 
be not clinically significant. The MedDRA will be used to code all unsolicited AEs. 
Refer to Section 8.2.10 for reporting of medical occurrences that begin before study intervention 
administration but after obtaining informed consent. 
8.2.9. 
Reporting Serious Adverse Events 
Any AE considered serious by the Investigator or that meets SAE criteria (Section 8.4.3) 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 required per applicable regulations. The Investigator is responsible for notifying 
the IRB or 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 e-mail or fax as provided on the form.  
Regulatory reporting requirements for SAEs are described in Section 8.4.9. 
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. 

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8.2.10. 
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 8.4.3. 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. 
8.2.11. 
Method of Detecting AEs and SAEs 
The eDiary has specifically been designed for this study by the Sponsor to collect solicited ARs. 
Refer to Section 8.2.5 for further details on the use of eDiary. Details on recording of solicited 
ARs in an eDiary are included in Section 8.4.4. 
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. 
8.2.12. 
Safety Laboratory Assessments 
Planned blood sampling for safety laboratory assessments will occur as indicated in the SoE 
(Table 1). Tests will include white blood cell count, hemoglobin, platelets, alanine 
aminotransferase, aspartate aminotransferase, total bilirubin, alkaline phosphatase, and 
creatinine. Laboratory tests will be performed by the central laboratory, unless otherwise 
specified. 

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8.2.13. 
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 Manual. 
8.2.14. 
Ancillary Supplies for Participant Use 
Study sites will distribute Sponsor-provided oral thermometers and rulers for use by participants 
in assessing body temperature and injection site reactions to record solicited ARs in eDiaries. 
Based on availability, smartphone devices may be provided to those participants who do not 
have their own device to use for eDiary activities. 
8.3. 
Immunogenicity Assessments 
Blood samples for humoral and cellular immunogenicity assessments will be collected at the 
timepoints indicated in the SoE (Table 1). The following analytes may be measured: 
• Serum antibody level as measured by HAI assay. 
• Serum nAb level as measured by MN assay or similar method, if necessary. 
Analytes may be measured using other exploratory serological assays and cellular 
immunogenicity assays. 
Sample aliquots will be designed to ensure that backup samples are available and that vial 
volumes are likely to be adequate for future testing needs. The actual time and date of each 
sample collected will be recorded in the eCRF, and unique sample identification will be utilized 
to allow for automated sample tracking and housing. Handling and preparation of the samples for 
analysis, as well as shipping and storage requirements, will be provided in a separate study 
manual. 
Measurement of antibody levels will be performed in a laboratory designated by the Sponsor. 
According to the ICF process (Section 11.1.6), serum from immunogenicity 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 viruses and across influenza viruses, and 
additional assay development. 
8.4. 
Safety Definitions and Related Procedures 
8.4.1. 
Influenza-Like Illness Case Definitions 
Protocol-defined ILI 
A protocol-defined ILI is determined by the occurrence of at least 1 respiratory illness symptom 
concurrently with at least 1 systemic symptom, or the occurrence of any 2 or more respiratory 
symptoms:  

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Table 6: 
Respiratory and Systemic Symptoms for Protocol-defined Influenza-like 
Illness 
Respiratory symptoms 
Systemic symptoms 
• 
Sore throat 
• 
Cough/rhinorrhea/nasal congestion (≥1 of 
the 3 symptoms count as 1 respiratory 
symptom) 
• 
Sputum production 
• 
Wheezing 
• 
Difficulty breathing 
• 
Body temperature >37.2°C [>99°F] 
• 
Chills 
• 
Tiredness 
• 
Headache 
• 
Myalgia 
• 
Nausea/vomiting 
• 
Diarrhea 
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 Protocol-defined 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-defined ILI performed at any 
setting during the study period. 
RT-PCR–confirmed CDC-defined Influenza Infection 
An RT-PCR–confirmed CDC-defined influenza infection is defined as a positive influenza result 
on a respiratory sample by RT-PCR performed at a Global Central Laboratory and/or a local 
certified laboratory within 7 days of onset of CDC-defined ILI symptoms at any time during the 
study period. 
Through Day 28, any illness assessed for protocol-defined ILI should be captured as an AE in 
EDC. Starting on Day 29, illnesses assessed for protocol-defined ILI should only be captured as 
AEs if they otherwise meet the criteria for reporting as an SAE (Section 8.4.3), MAAE 
(Section 8.4.5) or event leading to discontinuation from the study. An event should not be 
recorded as a MAAE based on visits to the clinical study site for protocol-required assessment of 
ILI symptoms and NP swab collection. 
8.4.2. 
Adverse Event 
An AE is defined as any untoward medical occurrence associated with the use of a 
pharmaceutical product, whether or not considered related to the product. 
A 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. 
An abnormal value or result from a clinical or laboratory evaluation can also indicate an AE if it 
is determined by the Investigator to be clinically significant. If this is the case, it must be 
recorded in the source document and as an AE in EDC. The evaluation that produced the value 
or result should be repeated until that value or result returns to normal or is stabilized and the 
participant’s safety is not at risk. 

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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 administration of the 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) although 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). 
An unsolicited AE is any AE reported by the participant that is not specified as a solicited AR 
(Section 8.4.4) 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 study 
intervention). 
8.4.3. 
Serious Adverse Events 
An AE (including a solicited AR) is considered a SAE if it results in any of the following 
outcomes: 
• Death 
A death that occurs during the study or that comes to the attention of the Investigator 
during the protocol-defined follow-up period must be reported to the Sponsor, whether or 
not it is considered related to the study intervention. 
• 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 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 

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accidental trauma (eg, sprained ankle) which may interfere with or prevent everyday life 
functions but do not constitute a substantial disruption. 
• 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. 
8.4.4. 
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 
administration of study intervention. An eDiary will prompt daily participant reporting of 
solicited ARs. 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 7, which are modified from the 
Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive 
Vaccine Clinical Trials (DHHS 2007b). 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 site staff in the EDC. 
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 in the EDC. 
If the participant reported an event that started after the solicited period (ie, after Day 7), it 
should be recorded as an AE in the EDC. 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 EDC:  
• Solicited AR that results in a visit to a 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 discontinuation). 
• Solicited AR lasting beyond 7 days post injection. 
• Solicited AR that otherwise meets the definition of an SAE. 

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Table 7: 
Solicited Adverse Reactions and Grades 
Reaction 
Grade 0 
(None) 
Grade 1 
(Mild) 
Grade 2 
(Moderate) 
Grade 3 
(Severe) 
Grade 4a 
(Life-
Threatening) 
Local 
Injection site pain 
None 
No 
interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
Requires 
emergency 
room visit or 
hospitalization 
Injection site 
erythema (redness) 
<25 mm/ 
<2.5 cm 
25-50 mm/ 
2.5-5 cm 
51-100 mm/ 
5.1-10 cm 
>100 mm/ 
>10 cm 
Necrosis or 
exfoliative 
dermatitis 
Injection site 
swelling/induration 
(hardness) 
<25 mm/ 
<2.5 cm 
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 
None 
No 
interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
Requires 
emergency 
room visit or 
hospitalization 
Systemic 
Headache 
None 
No 
interference 
with activity 
Some 
interference 
with activity 
Prevents daily 
activity 
Requires 
emergency 
room visit or 
hospitalization 
Fatigue 
None 
No 
interference 
with activity  
Some 
interference 
with activity 
Prevents daily 
activity 
Requires 
emergency 
room visit or 
hospitalization 
Myalgia (muscle 
aches all over body) 
None 
No 
interference 
with activity  
Some 
interference 
with activity 
Prevents daily 
activity  
Requires 
emergency 
room visit or 
hospitalization 

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Reaction 
Grade 0 
(None) 
Grade 1 
(Mild) 
Grade 2 
(Moderate) 
Grade 3 
(Severe) 
Grade 4a 
(Life-
Threatening) 
Arthralgia (joint 
aches in several 
joints) 
None 
No 
interference 
with activity  
Some 
interference 
with activity 
Prevents daily 
activity  
Requires 
emergency 
room visit or 
hospitalization 
Nausea/vomiting 
None 
No 
interference 
with activity 
or 1-2 
episodes/ 
24 hours 
Some 
interference 
with activity 
or 
>2 episodes/ 
24 hours 
Prevents daily 
activity, 
requires 
outpatient 
intravenous 
hydration 
Requires 
emergency 
room visit or 
hospitalization 
for 
hypotensive 
shock 
Chills 
None 
No 
interference 
with activity 
Some 
interference 
with activity 
not requiring 
medical 
intervention 
Prevents daily 
activity and 
requires 
medical 
intervention 
Requires 
emergency 
room visit or 
hospitalization 
Fever (oral) 
<38.0°C 
<100.4°F 
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 
Note: Events listed above but starting >7 days post study intervention will be recorded in EDC. Causality for each 
event reported in EDC will be determined per assessment by the Investigator. 
a 
Grading of Grade 4 events will be determined per Investigator and assessment is recorded in EDC. 
Source: Guidance for Industry – Toxicity Grading Scale for Heathy Adult and Adolescent Volunteers Enrolled in 
Preventive Vaccine Clinical Trials (DHHS 2007b). 
8.4.5. 
Medically Attended Adverse Events 
A MAAE is an AE that leads to an unscheduled visit to an HCP. This would include visits to a 
study clinic for unplanned 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 in EDC. 
An unscheduled visit for assessment of protocol-defined ILI (symptoms assessment and NP 
swab) is not considered a MAAE unless additional medical evaluation, including 
examinations/testing not required per protocol, and/or treatment is provided during the visit. 
8.4.6. 
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. 
In addition to anaphylaxis and myocarditis/pericarditis, AESIs for this protocol 
(thrombocytopenia and new onset of or worsening of neurologic diseases) are described in 
Section 11.3. 
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 EDC. If a site receives 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 e-mail or fax as provided on the form (Section 8.2.9). 
8.4.6.1. 
Anaphylaxis 
All suspected cases of anaphylaxis associated with study intervention administration should be 
recorded as AESIs, reported as an SAE, based on the criteria for a medically important event, 
unless the event meets other serious criteria. As an AESI and/or SAE, the event should be 
reported to the Sponsor or designee immediately and in all circumstances within 24 hours, per 
Section 8.2.9. 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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8.4.6.2. 
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 8.2.9). 
An independent CEAC will review reported cases of myocarditis, pericarditis, and 
myopericarditis to determine if they meet CDC criteria for “probable” or “confirmed” events 
(Section 8.5.2). 
The CDC Working Case Definitions are provided in Section 11.4 as guidance. 
8.4.7. 
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 8.4.3), 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 Preventive Vaccine Clinical Trials (DHHS 2007b) 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 8.4.4.  
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 site 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. 
8.4.8. 
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. 
8.4.9. 
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 toward the safety of participants and the safety of a study 
intervention under clinical investigation are met. 
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. 
8.5. 
Safety Oversight 
8.5.1. 
Internal Safety Team 
Safety monitoring for this study will include the study team members, inclusive of, at a 
minimum, the Sponsor medical monitor and a CRO medical monitor and an IST. The study team 
will conduct safety reviews during the study and will be responsible for notifying the IST of 
potential safety signal events. The IST will conduct a scheduled review of safety data after 
approximately 49 participants (approximately 7 per study arm) have completed the Day 8 visit, 
as well as ad hoc safety data reviews, if requested by the study monitor or study team. 
Enrollment will be ongoing while this review is conducted and if the study team has not 
identified any safety concerns.  
8.5.2. 
Independent Cardiac Event Adjudication Committee 
An independent CEAC of medically qualified personnel, including cardiologists, will review 
reported cases of myocarditis and pericarditis to determine if they meet CDC criteria of 
“probable” or “confirmed” events (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. 

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8.6. 
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: 
• Contact the Medical Monitor immediately. 
• Closely monitor the participant for any AE/SAE and laboratory abnormalities until 
the last safety follow-up visit. 
• Report any signs or symptoms associated with the overdose as an AE and record 
details in EDC. 
• Document the quantity of the excess dose in EDC. 
8.7. 
Pharmacokinetics 
Pharmacokinetic parameters are not evaluated in this study. 
8.8. 
Pharmacodynamics 
Pharmacodynamic parameters are not evaluated in this study. 
8.9. 
Biomarkers 
Immunogenicity assessments are described in Section 8.3. Biomarker assessments (to be 
determined) will be evaluated in this study, which may include genomic and transcriptomic 
studies. 
8.10. 
Health Economics 
Health economics are not evaluated in this study. 

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9. 
STATISTICAL CONSIDERATIONS 
9.1. 
Blinding and Responsibility for Analyses 
This is an open-label study. 
9.2. 
Statistical Hypotheses 
No formal hypotheses will be tested. The number of proposed participants is considered 
sufficient to provide a descriptive summary of the safety and immunogenicity of different dose 
levels of mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1. 
9.3. 
Sample Size Determination 
Approximately 700 participants will be randomized in this study, with approximately 100 
participants each in Vaccination Groups 1-7 (≥50 to ≤75 years of age). Details regarding the 
number of participants in each vaccination group are presented in Table 3. The probability of 
AEs based on sample size is presented in Table 8. With 100 participants in each group receiving 
the study intervention, there is an approximately 87% probability to observe at least 1 participant 
with an AE if the true incidence of the AE is 2%; if the true incidence rate is 3%, then the 
probability to observe an AE is approximately 95%. 
Table 8: 
Probability of AEs Based on Sample Size 
n 
True AE Rate 
Probability of 0 AE 
Probability of at Least 1 AE Observed 
100 
1.0% 
36.6% 
63.4% 
100 
2.0% 
13.3% 
86.7% 
100 
3.0% 
4.8% 
95.2% 
100 
4.0% 
1.7% 
98.3% 
AE = adverse event 

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9.4. 
Analysis Populations 
Table 9 describes the analysis populations. 
Table 9: 
Analysis Sets 
Set 
Description 
Randomization Set 
The randomization set consists of all participants who are randomly 
assigned. 
FASa 
The FAS consists of all randomly assigned participants who receive the 
study vaccination. 
PP Setb 
The PP Set consists of all participants in the FAS who comply with the 
injection schedule, comply with the timings of immunogenicity blood 
sampling to have a baseline and at least the Day 29 post-injection 
assessment, have no RT-PCR–confirmed influenza infection prior to 
Day 29 visit and have no major protocol deviations that impact the 
immune response. 
Safety Setc 
The safety set consists of all randomly assigned participants who receive 
the study vaccination. 
Solicited Safety Setd 
The solicited safety set consists of all participants in the safety set who 
contribute any solicited AR data. 
Abbreviations: AR = adverse reaction; FAS = full analysis set; PP = per-protocol; RT-PCR = reverse transcriptase 
polymerase chain reaction. 
a 
For the FAS, participants will be analyzed according to the group to which they were randomized. 
b 
The PP Set will be used as the primary analysis set for analyses of immunogenicity unless otherwise specified. 
Participants will be analyzed according to the group to which they were randomized. 
c 
The safety set will be used for all analyses of safety, except for the solicited ARs. Participants will be included 
in the vaccination group corresponding to what they actually received. 
d 
The solicited safety set will be used for the analyses of solicited ARs, and participants will be included in the 
vaccination group corresponding to what they actually received. 
9.5. 
Statistical Methods 
General Considerations: All analyses will be performed by treatment arm, unless otherwise 
specified. For categorical variables, frequencies and percentages will be presented. Continuous 
variables will be summarized using descriptive statistics (number of participants, mean, median, 
standard deviation, minimum, and maximum). 
9.5.1. 
Baseline Characteristics and Demographics 
Demographic variables (eg, age, sex, race, ethnicity, height, weight, and body mass index) and 
baseline characteristics will be summarized by vaccination group and overall. Summary statistics 
(mean and standard deviation for continuous variables and number and percentage for 
categorical variables) will be provided. 
9.5.2. 
Safety Analyses 
Safety and reactogenicity will be assessed by clinical review of all relevant parameters, including 
solicited ARs (local and systemic events), unsolicited AEs, SAEs, MAAEs, AEs leading to 
discontinuation, safety laboratory test results, vital signs, and physical examination findings. 

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Solicited ARs and unsolicited AEs will be coded by system organ class and preferred term 
according to the MedDRA for AR Terminology. The Toxicity Grading Scale for Healthy Adult 
and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials is used in this study 
with modification for solicited ARs and vital signs. 
All safety analyses will be based on the Safety Set, except summaries of solicited ARs, which 
will be based on the Solicited Safety Set.  
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 study intervention will be 
summarized. 
Number and percentage of participants with unsolicited AEs, SAEs, MAAEs, severe AEs, 
AESIs, and AEs leading to discontinuation from study vaccine or participation in the study will 
be summarized.  
Number of events of unsolicited AE, SAEs, AESIs, and MAAEs will be reported in summary 
tables accordingly. 
For all other safety parameters, descriptive summary statistics will be provided. 
For treatment-emergent safety laboratory tests results, the raw values and change from baseline 
values will be summarized by treatment arm and visit at each timepoint. 
The number and percentage of participants who have chemistry, hematology, and vital signs 
results below or above the normal laboratory ranges will be tabulated by timepoint. 
9.5.3. 
Immunogenicity Analyses 
The analyses of immunogenicity will be based on the PP Set. If the number of participants in the 
FAS and PP Set differ (defined as the difference divided by the total number of participants in 
the PP Set) by more than 10%, supportive analyses of immunogenicity data may be conducted 
using the FAS. 
For the immunogenicity endpoints, GM of specific antibody titers with corresponding 95% CI at each 
timepoint and GMFR of specific antibody titers with corresponding 95% CI at each postbaseline 
timepoint over preinjection baseline at Day 1 will be provided by treatment arm. Descriptive summary 
statistics including median, minimum, and maximum will also be provided. 
For summarizations of GMTs, GMFR, antibody titers reported as below LLOQ will be replaced 
by 0.5×LLOQ. Values that are greater than the ULOQ will be converted to the ULOQ. 
Seroconversion rate from baseline will be provided with a 2-sided 95% CI using the 
Clopper-Pearson method at each postbaseline timepoint. For HA, rate of seroconversion is 
defined as the proportion of participants with either a prevaccination HAI titer <1:10 and a 
postvaccination HAI titer >1:40 or a prevaccination HAI titer >1:10 and a minimum 4-fold rise 
in postvaccination HAI antibody titer.  
GMTRs with corresponding 95% CI will be calculated for each candidate vaccine group against 
matched mRNA-1010 controls (mRNA-1010, mRNA-1010.2 and mRNA-1010.3) after 
adjustment of baseline titers, at each available timepoint. 
Further details will be described in the SAP. 

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9.5.4. 
Exploratory Analyses 
Exploratory analyses will be described in the SAP. 
9.5.5. 
Subgroup Analyses 
The protocol does not define any formal subgroup analyses. However, future subgroups may be 
defined in the SAP. 
9.6. 
Planned Analyses 
9.6.1. 
Interim Analyses 
In this study, one IA is planned and will be performed after participants have completed Day 29 
and will include, at a minimum, cleaned data from available safety and immunogenicity datasets. 
The IA will include all immunogenicity data up to Day 29, the solicited reactogenicity data in the 
first 7 days after vaccination, any unsolicited AEs within 28 days after vaccination, and other 
safety data up to Day 28. 
The final clinical study report will include full analyses of safety and immunogenicity data 
available through Day 181(Month 6)/EoS.  
The SAP will describe the planned interim and final analyses in greater detail. 

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10. 
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Aretz HT, Billingham ME, Edwards WD, Factor SM, Fallon JT, Fenoglio JJ Jr, et al. 
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Centers for Disease Control and Prevention (CDC). CDC seasonal flu vaccine effectiveness 
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Department of Health and Human Services (DHHS), Food and Drug Administration, Center for 
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Vaccines.pdf. 
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 
2007b [cited 2021 Aug 19]. Available from: 
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Dunning AJ, DiazGranados CA, Voloshen T, Hu B, Landolfi VA, Talbot HK. Correlates of 
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Vaccine Immunol. 2016;23(3):228-35. 
European Medicines Agency (EMA). Committee for Medicinal Products for Human Use. 
Guideline on influenza vaccines: non-clinical and clinical module. London, 21 July 2016. 
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clinical-module_en.pdf. 
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: 
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ClinicalTrials.gov [internet]: National Library of Medicine (US). 2022 Jun 13 [updated 
2022 Sep 21; cited 2022 Nov 17]. Available from: 
https://clinicaltrials.gov/ct2/show/NCT05415462. NLM identifier: NCT05415462. 

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ModernaTX, Inc. A Study of mRNA-1010 Seasonal Influenza Vaccine in Adults 50 Years Old 
and Older. In: ClinicalTrials.gov [internet]: National Library of Medicine (US). 2022 Oct 04 
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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 
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Riedel S, Hobden JA, Miller S, Morse SA, Mietzner TA, Detrick B, et al. Jawetz, Melnick & 
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Rockman S, Laurie KL, Parkes S, Wheatley A, Barr IG. New technologies for influenza 
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Shimabukuro TT, Cole M, Su JR. Reports of anaphylaxis after receipt of mRNA COVID-19 
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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 International Ethical Guidelines. 
• Applicable ICH 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 by the Investigator and reviewed 
and approved by the IRB before the study is initiated. 
• Any amendments to the protocol will require IRB 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 annually or 
more frequently in accordance with the requirements, policies, and procedures 
established by the IRB. 
− Notifying the IRB of SAEs or other significant safety findings as required by IRB 
procedures. 
− Providing oversight of the conduct of the study at the site and adherence to 
requirements of 21 CFR, ICH GCP guidelines, the IRB, and all other applicable 
local regulations. 
11.1.2. 
Study Monitoring 
Before an investigational study site can enter a participant into the study, the Sponsor or its 
representatives will visit the study site for the following: 
• 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 the Sponsor or its representatives. 
This will be documented in a Clinical Study Agreement between the Sponsor, the 
designated CRO, and the Investigator. 
According to ICH GCP guidelines, 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 the Sponsor 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 
monitoring, audits, IRB review, and inspection by providing direct access to the source data 

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and/or documents. In addition, the study monitor will explain to and interpret for the Investigator 
all regulations applicable to the clinical evaluation of IP 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 the Sponsor or a representative will have regular contacts with the 
study site, for the following purposes: 
• 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 IP 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 that AEs and SAEs have been properly documented on eCRFs, that any 
SAEs have been forwarded to the Sponsor and that those SAEs that meet criteria for 
reporting have been forwarded to the IRB. 
The monitor will be available between visits if the Investigator(s) or other staff needs 
information or advice. 
11.1.3. 
Audits and Inspections 
The Sponsor, their designee(s), the IRB, 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 the Sponsor Inc., their designee(s), the IRB, 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 the Sponsor, a regulatory authority, and the IRB may visit the 
study 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 whether data 
were recorded, analyzed, and accurately reported according to the protocol, ICH GCP E6 [R2], 
and any applicable regulatory requirements. The Investigator should contact the Sponsor. 
immediately if contacted by a regulatory agency about an inspection. 
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 ICF and 
recruitment materials must be maintained by the Investigator and made available for inspection. 

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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 study. These 
include, but are not limited to, services that provide a means to identify potential participants and 
direct them to participating clinical study sites, participant support services such as concierge, 
and study 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 meet the requirements of 21 CFR 50, local regulations, 
ICH guidelines, Health Insurance Portability and Accountability Act (HIPAA) requirements, 
where applicable, and the IRB or study site. All consent documents will be approved by the 
appropriate IRB. The actual ICF used at each study site may differ, depending on local 
regulations and 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 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 him/her in a timely manner. 
Such information will be provided via a revised ICF or an addendum to the original ICF. 
The Investigator or his/her 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. 
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 

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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 his/her source 
medical records by study monitors, auditors, the IRB, 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 he/she/they is/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 declines to participate in this optional research will not provide this separate signature. 
11.1.7. 
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 that would make the participant identifiable will not be transferred. 
The participant must be informed that his/her/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 his/her/their medical records may be examined by Clinical 
QA auditors or other authorized personnel appointed by the Sponsor, by appropriate IRB 
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 HCP of his/her/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, the relevant regulatory authority, or the IRB. 

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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. 
11.1.8. 
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-1011.1, 
mRNA-1011.2, mRNA-1012.1, 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. 
11.1.9. 
Dissemination of Clinical Study Data 
The Sponsor 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, European Union clinicaltrialregister (eu.ctr), etc., as well as some 
national registries. 
11.1.10. 
Data Quality Assurance and Quality Control 
Data collection is the responsibility of the clinical study staff at the site under the supervision of 
the 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 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. 

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• 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 review, and 
regulatory agency inspections and provide direct access to source data documents. 
• 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 onsite 
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, 
CROs). 
• Study monitors will perform ongoing source data verification to confirm that data 
entered into the eCRF by authorized study site staff 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 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. 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 QA representative from the 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 
onsite inspections/audits and source data checks. Direct access to source documents is required 
for the purpose of these periodic inspections/audits. 
11.1.11. 
Source Documents 
Source documents are original documents or certified copies and include, but are not limited to, 
eDiaries, medical and hospital records, screening logs, ICFs, 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. 

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Data reported on the case report form 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. 
The Sponsor 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, study site, or office charts and the signed ICFs are to be included in the 
Investigator’s files with the participant’s study records. 
11.1.12. 
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 the Sponsor 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. 
11.1.13. 
Study and Site Closure 
If the study is prematurely terminated or suspended, the Sponsor shall promptly inform the 
Investigators, the IRBs, the regulatory authorities, and any CRO(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 ensure 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 the following: 
• Continuation of the study represents a significant medical risk to participants. 
• Failure of the Investigator to comply with the protocol, the requirements of the IRB 
or local health authorities, the Sponsor's procedures, or ICH GCP guidelines. 
• Inadequate recruitment of participants by the Investigator. 
• Discontinuation of further mRNA-1011.1, mRNA-1011.2, and mRNA-1012.1 
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. 

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11.1.14. 
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 the 
Sponsor. 

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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): 
a. Following menarche 
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. 
− A high FSH level in the postmenopausal range may be used to confirm a 
postmenopausal state in women not using hormonal contraception or HRT. 
However, in the absence of 12 months of amenorrhea, confirmation with more 
than one FSH measurement is required. 
− 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: 
− Documented hysterectomy 
− Documented bilateral salpingectomy 
− Documented bilateral oophorectomy 
− Documented tubal ligation 
− For individuals with permanent infertility due to an alternate medical cause other 
than the above, (eg, Müllerian agenesis, androgen insensitivity, gonadal 
dysgenesis), Investigator discretion should be applied to determining study entry. 
Note: Documentation can come from the study site staff’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. The following are 
examples: 
• Barrier method (such as condoms, diaphragm, or cervical cap) used in conjunction 
with spermicide 
• Intrauterine device 

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• Prescription hormonal contraceptive taken or administered via oral (pill), transdermal 
(patch), subdermal, or IM route 
• Sterilization of a female participant’s monogamous male partner prior to entry into 
the study 
Note that periodic abstinence (eg, calendar, ovulation, symptothermal, postovulation 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: Adverse Events of Special Interest Terms 
Investigators should report all events that fall into the categories presented in Table 10 as an 
AESI per the reporting processes in Section 8.2.9. 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 10: 
Adverse Events of Special Interest 
Medical Concept 
Additional Notes 
Thrombocytopenia 
• 
Platelet counts <125×109  
• 
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 (ADEM) 
• 
Idiopathic peripheral facial nerve palsy (Bell’s palsy) 
• 
Seizures including but not limited to febrile seizures and/or 
generalized seizures/convulsions 
Anaphylaxis 
• 
Anaphylaxis associated with IP administration as defined per 
protocol (Section 8.4.6.1) 
• 
Follow reporting procedures in protocol (Section 8.2.9) 
Myocarditis/Pericarditis 
• 
Myocarditis 
• 
Pericarditis 
• 
Myopericarditis 
Abbreviation: HELLP = hemolysis, elevated liver enzymes, and low platelet count. 
 
 
 

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11.4. 
APPENDIX 4: CDC Working Case Definition of Pericarditis, 
Myocarditis, and Myopericarditis Occurring after Receipt of 
COVID-19 mRNA Vaccines 
The CDC Working Case Definitions of probable and confirmed myocarditis, pericarditis, and 
myopericarditis (Gargano et al 2021) are provided in Table 11 as guidance. 
Table 11: 
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. 
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. 
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. 

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Condition 
Definition 
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 
reported cases of myocarditis, pericarditis, and myopericarditis to determine if they meet Centers for Disease 
Control and Prevention criteria for “probable” or “confirmed” events, (Gargano et al 2021), and provide the 
assessment to the Sponsor. 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). 
 

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