A Prospective, Randomized, Clinical Trial to Compare Adverse Birth Outcomes in Pregnant Women Receiving Quadrivalent Recombinant Influenza Vaccine (RIV4) Versus Quadrivalent Inactivated Influenza Vaccine (IIV4)
Phase: PHASE4
Conditions: Safety, Adverse Event Following Immunisation, Birth Outcomes
Sponsor: Duke University

Safety of RIV4 versus IIV4 in Pregnancy 
 
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A Prospective, Randomized, Clinical Trial to Compare Adverse Birth Outcomes in 
Pregnant Women Receiving Quadrivalent Recombinant Influenza Vaccine (RIV4) versus 
Quadrivalent Inactivated Influenza Vaccine (IIV4) 
 
Short Title: Safety of RIV4 versus IIV4 in Pregnant Women  
 
 
Centers for Disease Control and Prevention  
Clinical Immunization Safety Assessment (CISA) Project  
 
 
Lead Site Principal Investigator: Geeta K. Swamy, MD 
Lead Site Sub-principal Investigator: Sarah Dotters-Katz, MD, MEd 
 
Contributing Site Principal Investigator: Elizabeth Schlaudecker, MD 
Contributing Site Sub-principal Investigator: Emily DeFranco, DO, MS 
 
Contributing Site Principal Investigator: Stephen I. Pelton, MD 
Contributing Site Sub-principal Investigator: Glenn Markenson, MD 
 
Centers for Disease Control and Prevention (CDC) Principal Investigator: Karen R. 
Broder, MD 
CDC Sub-principal Investigator: Naomi Tepper, MD 
 
 
NCT03969641 
 
Version Number: 4.0 
 
15 Mar 2022 
 
 
 
 
 
 
 

Safety of RIV4 versus IIV4 in Pregnancy 
 
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STATEMENT OF COMPLIANCE 
• 
This trial will be conducted in compliance with the protocol, the International 
Conference on Harmonization (ICH) Guideline E6-Good Clinical Practice (GCP), 
and the applicable guidelines and regulatory requirements from the United States 
(US) Code of Federal Regulations (CFR), 45 CFR Part 46. 
• 
All study personnel with subject contact have completed Human Subjects 
Protection Training. 
 
 
 

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TABLE OF CONTENTS 
 
PROTOCOL SUMMARY .............................................................................................................................................. 5 
1 
BACKGROUND .................................................................................................................................................. 9 
1.1 
BACKGROUND .................................................................................................................................................................... 9 
1.2 
SUMMARY & RATIONALE ............................................................................................................................................... 10 
2 
STUDY OBJECTIVES ..................................................................................................................................... 10 
2.1 
STUDY OUTCOME MEASURES ........................................................................................................................................ 11 
2.1.1 
Primary Outcome Measure: ........................................................................................................................ 11 
2.1.2 
Secondary Outcome Measures: .................................................................................................................. 11 
2.1.3 
Exploratory Outcome Measures: ............................................................................................................... 11 
3 
STUDY DESIGN ............................................................................................................................................... 12 
3.1 
MAIN STUDY DESIGN ....................................................................................................................................................... 12 
3.2 
LABORATORY STUDIES.................................................................................................................................................... 12 
3.2.1 
Serologic studies .............................................................................................................................................. 12 
4 
STUDY ENROLLMENT AND WITHDRAWALS ...................................................................................... 13 
4.1 
PARTICIPANT INCLUSION CRITERIA ............................................................................................................................. 13 
4.2 
PARTICIPANT EXCLUSION CRITERIA ............................................................................................................................ 14 
4.3 
RECRUITMENT ................................................................................................................................................................. 15 
4.4 
REASONS FOR AND HANDLING OF WITHDRAWALS ................................................................................................... 15 
4.5 
TERMINATION OF STUDY ............................................................................................................................................... 15 
5 
STUDY SCHEDULE, PROCEDURES, & EVALUATIONS ........................................................................ 15 
5.1 
SCHEDULE OF EVENTS .................................................................................................................................................... 15 
5.2 
TREATMENT ASSIGNMENT PROCEDURES.................................................................................................................... 20 
5.2.1 
Randomization ................................................................................................................................................. 20 
5.2.2 
Blinding ............................................................................................................................................................... 20 
5.2.3 
Vaccine Supply, Storage, and Administration...................................................................................... 20 
5.3 
REACTOGENICITY AND SAFETY ASSESSMENTS ........................................................................................................... 21 
5.4 
BIOSPECIMENS COLLECTION & HANDLING ................................................................................................................. 23 
5.4.1 
Serum ................................................................................................................................................................... 23 
6 
LABORATORY ANALYSES .......................................................................................................................... 24 
6.1 
INFLUENZA LABORATORY ANALYSIS ........................................................................................................................... 24 
7 
STATISTICAL CONSIDERATIONS ............................................................................................................. 24 
7.1 
DEFINITIONS .................................................................................................................................................................... 24 
7.2 
SAMPLE SIZE AND POWER ESTIMATION ..................................................................................................................... 24 
7.3 
ANALYSIS PLAN ............................................................................................................................................................... 25 
7.3.1 Study Populations .................................................................................................................................................. 25 
7.3.2   Alpha Level ............................................................................................................................................................. 25 
7.3.3   Primary Objective ................................................................................................................................................ 25 
7.3.4 
Secondary Objective 1. .................................................................................................................................. 26 
7.3.5    Secondary Objective 2 ....................................................................................................................................... 26 
7.3.6    Secondary Objective 3 ....................................................................................................................................... 26 
7.3.7    Secondary Objective 4 ....................................................................................................................................... 26 
7.3.8 
Exploratory Objective 1 ................................................................................................................................ 26 
7.3.9     Exploratory Objective 2 ................................................................................................................................... 27 
7.3.10 
Exploratory Objective 3 .......................................................................................................................... 27 

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7.3.11 
Exploratory Objective 4 .......................................................................................................................... 27 
7.3.12 
Exploratory Objective 5 .......................................................................................................................... 27 
7.3.13 
Sensitivity analysis .................................................................................................................................... 27 
7.3.14 
Interim Safety Data Review .................................................................................................................. 28 
7.3.16 
Further analysis ......................................................................................................................................... 28 
7.4 
DATA MANAGEMENT PLAN ........................................................................................................................................... 28 
7.4.1 Research Electronic Data Capture (REDCap) ............................................................................................. 29 
7.4.2 
Role of the CDC Investigators in the Project ......................................................................................... 30 
8 
HUMAN PARTICIPANTS ............................................................................................................................. 30 
8.1 
HUMAN PARTICIPANTS INVOLVEMENT, CHARACTERISTICS, AND DESIGN ............................................................ 30 
8.2 
SOURCES OF MATERIAL .................................................................................................................................................. 30 
8.3 
POTENTIAL RISKS AND BENEFITS ................................................................................................................................ 30 
8.4 
ADEQUACY OF PROTECTION AGAINST RISKS .............................................................................................................. 31 
8.4.1 
Protections against Risk ............................................................................................................................... 31 
8.4.2 
ClinicalTrials.gov Requirements ............................................................................................................... 32 
9.0 
HUMAN PARTICIPANTS .................................................................................................................................................. 32 
9.1.1 
Vulnerable Subjects Research .................................................................................................................... 32 
REFERENCES ............................................................................................................................................................. 33 
 
 

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PROTOCOL SUMMARY 
 
Title:  
A Prospective, Randomized, Clinical Trial to Compare Adverse 
Birth Outcomes in Pregnant Women Receiving Quadrivalent 
Recombinant Influenza Vaccine (RIV4) versus Quadrivalent 
Inactivated Influenza Vaccine (IIV4) 
 
Phase: 
Phase 4 
Population: 
430 adult pregnant women ≥ 18 years at ≤ 34 weeks gestation  
who plan on receiving RIV4 or IIV4 during the current pregnancy 
in accordance with the Advisory Committee on Immunization 
Practices (ACIP) and American College of Obstetricians & 
Gynecologists (ACOG) national recommendations.    
Clinical Sites: 
Three: Duke University (Lead); Cincinnati Children’s Hospital 
Medical Center (Contributor); Boston Medical Center 
(Contributor) 
Study Duration: 
60 months (approximately 12 months to recruit/enroll), 
maximum of 24 months to follow, 24 months to perform analysis 
and laboratory assays  
Participant Duration: 
Up to 12 months depending upon gestational age at enrollment 
and delivery.  Will be followed for 90 days postpartum. 
Description of Study 
Procedures: 
This is a prospective, randomized clinical trial. During the 
study, pregnant women will be randomized (1:1) to receive 
RIV4 or IIV4.  Vaccines will be administered by licensed 
providers.   
 
Prior influenza vaccine history will be verified by medical 
record review when possible.  
 
Injection-site (local) and systemic reaction data will be 
assessed on vaccination day and during the 8 days following 
vaccination using either identical web-based or paper diaries, 
depending on study participant preference.  
 
Maternal serum samples will be collected for antibody titers 
relevant to Influenza at time points that include: prior to 
vaccination and ~29 days post vaccination.  At Duke 
University, maternal and infant cord blood will be collected at 
delivery and analyzed for the same antibody titers. At other 
clinical sites, these delivery samples will only be collected if 
feasible.  
 

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Pregnant women will be followed through 90 days postpartum. 
with comprehensive obstetric and neonatal outcomes obtained 
from medical record review.   
Objectives: 
Primary Objectives: 
• 
To compare the proportions of adverse birth outcomes 
in pregnant women vaccinated with RIV4 versus IIV4   
 
Secondary Objectives: 
• 
To compare proportions of preterm birth after RIV4 
versus IIV4 vaccination  
• 
To compare proportions of combined fetal and neonatal 
death after RIV4 versus IIV4 vaccination  
• 
To compare proportions of spontaneous abortion after 
RIV4 versus IIV4 vaccination  
• 
To compare proportions of moderate/severe solicited 
reactogenicity events in pregnant women vaccinated 
with RIV4 versus IIV4 
 
Exploratory Objectives: 
• 
To compare and describe serious adverse events 
(SAE) in pregnant women vaccinated with RIV4 versus 
IIV4 
• 
To compare proportions of adverse pregnancy and birth 
outcomes of clinical interest after RIV4 versus IIV4 
vaccination 
• 
To compare and describe health outcomes through 90 
days of life in infants born to women after RIV4 versus 
IIV4 vaccination 
• 
To compare maternal immune responses to influenza 
antigens after RIV4 versus IIV4 vaccination 
• 
To compare cord blood antibody levels for influenza 
antigens after RIV4 versus IIV4 vaccination 
Outcome Measures: 
Primary:  
• 
Proportions of adverse birth outcomes in pregnant 
women vaccinated with RIV4 versus IIV4 
 
Secondary:  
• 
Proportions of preterm birth after RIV4 versus IIV4 
vaccination  
• 
Proportions of combined fetal and neonatal death after 
RIV4 versus IIV4 vaccination 
• 
Proportions of spontaneous abortion after RIV4 versus 
IIV4 vaccination 

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• 
Proportions of pregnant women with moderate/severe 
solicited reactogenicity events (local and systemic) 
within 8 days after vaccination with RIV4 versus IIV4 
 
Exploratory: 
• 
Frequency and descriptions of serious adverse events 
in pregnant women vaccinated with RIV4 versus IIV4 
during the 42 days after vaccination 
• 
Frequency and descriptions of serious adverse events 
in pregnant women vaccinated with RIV4 versus IIV4 
after vaccination during the study 
• 
Proportions of infants born small for gestational age 
after RIV4 versus IIV4 vaccination 
• 
Proportion of pregnant women with clinical 
chorioamnionitis, after RIV4 versus IIV4 vaccination 
• 
Proportion of women with preeclampsia or eclampsia 
after RIV4 versus IIV4 vaccination 
• 
Proportion of infants with medically-attended adverse 
events through 90 days of life after maternal RIV4 
versus IIV4 vaccination 
• 
Frequency and description of SAEs in infants through 
90 days of life after maternal RIV4 versus IIV4 
vaccination 
• 
Proportion of infants with neonatal death after maternal 
RIV4 versus IIV4 vaccination 
• 
Proportion of pregnant women achieving 
seroconversion at day 29 after RIV4 versus IIV4 
vaccination [a Hemagglutination Inhibition Assay (HAI) 
titer > 1:40 at day 29 if the baseline titer is < 1:10 or a 
minimum four-fold rise in HAI titer if the baseline titer is 
> 1:10) for each influenza vaccine antigen] 
• 
Proportion of pregnant women with a seroprotective 
HAI titer (≥ 1:40) post-immunization at day 29 after 
RIV4 versus IIV4 vaccination for each influenza vaccine 
antigen 
• 
The maternal geometric mean HAI titer (GMT) pre and 
post-vaccination at day 29 after RIV4 versus IIV4 for 
each influenza vaccine antigen and the post/pre-
vaccination ratio  
• 
Proportion of infants with cord blood seroprotective HAI 
titer (≥ 1:40) for each influenza vaccine antigen after 
maternal RIV4 versus IIV4 vaccination 
• 
Infant cord blood geometric mean HAI titer (GMT) for 
each influenza vaccine antigen after maternal RIV4 
versus IIV4 vaccination 
• 
Ratio of cord blood to maternal influenza antibody titers 
at time of delivery for each influenza vaccine antigen 
after maternal RIV4 versus IIV4 vaccination 

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Estimated Time to Complete 
Enrollment: 
Approximately 6 months for enrollment for the 2019-20 
influenza season and 6 months for enrollment during the 2020-
2021 influenza season. 

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1 BACKGROUND  
1.1 Background 
Pregnant women are at an increased risk for influenza-related morbidity due to changes 
in immunology and cardiorespiratory physiology.1 Influenza-infected pregnant women 
have higher rates of hospitalization and cardiopulmonary complications during influenza 
seasons, compared to the general public.2 Further, some studies suggest influenza can 
be associated with adverse birth outcomes such as preterm birth and fetal demise.3  
Complications of influenza during pregnancy can be even higher during pandemics, as 
seen in the 2009 H1N1 pandemic when the preterm birth rate rose threefold among 
infected pregnant women and 5% of all related deaths reported to CDC occurred in 
pregnant women, yet they only encompass 1% of the total population.4  The Advisory 
Committee on Immunization Practices (ACIP) and the American College of Obstetricians 
& Gynecologists (ACOG) have recommend an age-appropriate inactivated influenza 
vaccine (IIV) for all women who are or will be pregnant during influenza season.5,6 Initial 
recommendations for IIV administration during pregnancy were extrapolated from the 
documented efficacy and safety of IIV in non-pregnant adults. Until the 2009 pandemic, 
there were only a few small-scale studies on the safety and immunogenicity of maternal 
influenza vaccination.7 Recent large cohort studies and randomized controlled trials have 
supported the safety and effectiveness of IIV in pregnancy.8-12 
Due to continuous evolution of influenza glycoproteins, the World Health Organization 
(WHO) meets to consider and make recommendations for updates in influenza vaccine 
composition twice a year. For the northern hemisphere, the WHO generally makes these 
recommendations in February.  The U.S. Food and Drug Administration (FDA) Vaccines 
and Related Biological Products Advisory Committee (VRBPAC) subsequently meets in 
late February or early March to determine composition of the vaccines to be produced, 
distributed, and administered in the United States starting late summer of the same year. 
Since the 1940s, standard IIV manufacturing has involved the use of embryonated hen 
eggs. While effective, this technology is hampered by the requirement for pathogen-free 
eggs and specialized manufacturing facilities in which throughput can only be amplified 
by increasing the number of eggs. This process is also vulnerable to avian influenza 
viruses. Finally, the lengthy production process hinders potential for rapid scale-up in 
response to emerging needs such as a pandemic or supply shortage.  
HHS has supported development of alternate influenza vaccine technology as a 
component of influenza preparedness.13 In January 2013 the U.S. FDA approved 
Flublok®, the first recombinant influenza vaccine (RIV), RIV contains influenza virus 
antigens manufactured using an insect baculovirus expression system and recombinant 
technology. RIV does not contain ovalbumin. FDA licensed a quadrivalent formulation of 
RIV, Flublok® Quadrivalent (RIV4) in 2016.14  RIV may offer some advantages to egg-
based vaccines.  Production time during a pandemic may be shorter, and permit earlier 
availability of vaccine (though this has not yet been demonstrated).  In addition, it is not 
subject to egg-adaptation mutations that can occur in influenza vaccine virus strains as 
they are passaged through eggs.  Some evidence suggests that such mutations may 
affect vaccine effectiveness.15  However, specific effectiveness data for RIV are currently 
limited due to its relatively limited use to date.  
In 2017, ACIP expanded its influenza vaccine recommendation for pregnant women to 
include RIV with no stated preference between RIV and IIV products.6  Data on uptake of 
RIV in pregnant women following the 2017 ACIP recommendations to include this 
vaccine in its maternal influenza recommendations are not available.  Data from CDC’s 
Vaccine Safety Datalink (VSD) suggest that use of RIV in the adult population has been 

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limited (VSD, unpublished data, 2019). However, it is possible that use among pregnant 
women might increase during a pandemic or a season of vaccine shortage, as RIV might 
be available earlier than other vaccines, and pregnant women are among the 
populations recommended to be a focus for vaccination efforts when vaccine supply is 
limited. Furthermore, use of RIV may become more widespread in future seasons due to 
concerns about decreased vaccine effectiveness related to egg adaptation.   
 
Although approved for adults ≥ 18 years, prelicensure studies for RIV specifically 
excluded pregnant women. To date, safety data on RIV use during pregnancy are limited 
to manufacturer registry data, regulatory data that describes incidental pregnancies that 
occurred during the course of clinical trials, and passive surveillance data, including data 
obtained from a large influenza vaccination campaign in Mongolia.6 These data are 
reassuring, with no indication of adverse reactogenicity or obstetric events. While the 
Vaccine Adverse Event Reporting System (VAERS) can provide information on safety of 
licensed vaccines, there are inherent limitations of this passive surveillance system. In 
the VSD, the number of RIV doses administered to pregnant women is expected to be 
insufficient for comparative studies. ACIP stated during their June 2017 meeting that 
safety data on RIV in pregnant women are limited.6 Understanding whether benefit is 
conferred with adequate protection against influenza illness in pregnant is also 
important. Given the obligatory changes in maternal immunology to allow for fetal 
tolerance, the immunogenicity of RIV during pregnancy should also be assessed.  
1.2 Summary & Rationale 
ACIP currently recommends that pregnant women aged ≥ 18 years receive an age-
appropriate IIV or RIV (Flublok® Quadrivalent. While there is no specific reason to 
expect RIV to be unsafe during pregnancy, the lack of systematically collected data on 
the safety of RIV in pregnancy places a burden on obstetric providers and pregnant 
women to assess risk-benefit balance in the context of limited data. Establishing the 
safety of RIV is imperative to support current use among pregnant women during 
seasonal vaccination efforts and in the event that RIV is widely used during a pandemic 
or supply shortage when pregnant women may be prioritized for vaccination. 
Systematically collected data from a rigorous randomized controlled trial of RIV in 
pregnant women will provide much needed information on the overall safety for pregnant 
women and their infants, including adverse pregnancy outcomes, local and systemic 
reactogenicity, and vaccine-related adverse events.   Additionally, assessing 
immunogenicity following maternal RIV will add to the evidence base for maternal 
vaccination.  
 
2 STUDY OBJECTIVES 
Primary Objective: 
• 
PO1: To compare the proportions of adverse birth outcomes in pregnant women 
vaccinated with RIV4 versus IIV4.   
Research hypothesis: The proportion of pregnant women with adverse birth 
outcomes will be noninferior (not higher) after receipt of RIV4 compared to IIV4 
 
 
 
 

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Secondary Objectives: 
• 
SO1: To compare proportions of preterm birth after RIV4 versus IIV4 vaccination  
• 
SO2: To compare proportions of combined fetal and neonatal death after RIV4 
versus IIV4 vaccination 
• 
SO3: To compare proportions of spontaneous abortion after RIV4 versus IIV4 
vaccination 
• 
SO4: To compare proportions of moderate/severe solicited reactogenicity events 
in pregnant women vaccinated with RIV4 versus IIV4  
 
Exploratory Objectives: 
• 
EO1: To compare and describe serious adverse events (SAE) in pregnant 
women vaccinated with RIV4 versus IIV4 
• 
EO2: To compare proportions of adverse pregnancy and birth outcomes of 
clinical interest after RIV4 versus IIV4 vaccination 
• 
EO3: To compare and describe health outcomes through 90 days of life in infants 
born to women after RIV4 versus IIV4 vaccination 
• 
EO4: To compare maternal immune responses to influenza antigens after RIV4 
versus IIV4 vaccination  
• 
EO5: To compare cord blood antibody levels for influenza antigens after RIV4 
versus IIV4 vaccination  
 
2.1 Study Outcome Measures 
2.1.1 Primary Outcome Measure:  
POM1: Proportions of adverse birth outcomes in pregnant women vaccinated 
with RIV4 versus IIV4   
Adverse birth outcome is a composite of occurrence of at least one of the 
following: preterm birth, spontaneous abortion, fetal death, or neonatal death. 
2.1.2 Secondary Outcome Measures: 
 
• 
SOM1: Proportions of preterm birth after RIV4 versus IIV4 vaccination 
• 
SOM2: Proportions of combined fetal and neonatal death after RIV4 versus IIV4 
vaccination 
• 
SOM3: Proportions of spontaneous abortion after RIV4 versus IIV4 vaccination 
• 
SOM4: Proportions of pregnant women with moderate/severe solicited 
reactogenicity events (local and systemic) within 8 days after vaccination with 
RIV4 versus IIV4 
 
2.1.3 Exploratory Outcome Measures: 
 
• 
EOM1.1: Frequency and descriptions of serious adverse events in pregnant 
women vaccinated with RIV4 versus IIV4 during the 42 days after vaccination  
• 
EOM1.2: Frequency and descriptions of serious adverse events in pregnant 
women vaccinated with RIV4 versus IIV4 during the study 
• 
EOM2.1. Proportions of infants born small-for-gestational age after RIV4 versus 
IIV4 vaccination. 

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• 
EOM2.2: Proportion of pregnant women with clinical chorioamnionitis after RIV4 
versus IIV4 vaccination 
• 
EOM2.3: Proportion of women with preeclampsia or eclampsia after RIV4 versus 
IIV4 vaccination  
• 
EOM3.1: Proportion of infants with medically-attended events through 90 days of 
life after maternal RIV4 versus IIV4 vaccination  
• 
EOM3.2: Frequency and description of SAEs in infants through 90 days of life 
after maternal RIV4 versus IIV4 vaccination.  
• 
EOM3.3 Proportion of infants with neonatal death after maternal RIV4 versus 
IIV4 vaccination  
• 
EOM4.1: Proportion of pregnant women achieving seroconversion at day 29 after 
RIV4 versus IIV4 vaccination [a Hemagglutination Inhibition Assay (HAI) titer > 
1:40 at day 29 if the baseline titer is < 1:10 or a minimum four-fold rise in HAI titer 
if the baseline titer is > 1:10) for each influenza vaccine antigen] 
• 
EOM4.2: Proportion of pregnant women with a seroprotective HAI titer (≥ 1:40) 
post-immunization at day 29 after RIV4 versus IIV4 vaccination for each 
influenza vaccine antigen 
• 
EOM4.3: The maternal geometric mean HAI titer (GMT) pre and post-vaccination 
at day 29 after RIV4 versus IIV4 for each influenza vaccine antigen and the 
post/pre-vaccination ratio 
• 
EOM5.1: Proportion of infants with cord blood seroprotective HAI titer (≥ 1:40) for 
each influenza vaccine antigen after maternal RIV4 versus IIV4 vaccination  
• 
EOM5.2: Infant cord blood geometric mean HAI titer (GMT) for each influenza 
vaccine antigen after maternal RIV4 versus IIV4 vaccination 
• 
EOM5.3: Ratio of cord blood to maternal influenza antibody titers at time of 
delivery for each influenza vaccine antigen after maternal RIV4 versus IIV4 
vaccination  
 
3 STUDY DESIGN 
3.1 Main study design 
This study is a prospective, randomized clinical trial of approximately 430 pregnant 
women enrolled at Duke University Medical Center (Lead Contractor), Cincinnati 
Children’s Hospital Medical Center (Contributing Contractor), and Boston Medical 
Center (Contributing Contractor). Pregnant women ≥ 18 years of age at ≤ 34 weeks 
gestation, will be enrolled and randomized 1:1 to receive either quadrivalent 
recombinant influenza vaccine (RIV4) or quadrivalent inactivated influenza vaccine 
(IIV4). The designated vaccine brands for this study are Flublok® quadrivalent (Sanofi) 
and quadrivalent Flulaval® (GSK) (comparator IIV4). However, the choice of IIV4 
vaccine administered will be based on availability from manufacturers prior to the 2019-
2020 and 2020-2021 influenza seasons. 
After vaccination, participants and their infants will be followed to assess adverse 
pregnancy and birth outcomes, maternal vaccine reactogenicity, immunogenicity, 
serious adverse events, and short-term infant outcomes. Maternal and infant outcomes 
will be collected by medical record review from enrollment through 90 days postpartum.  
3.2 Laboratory studies 
3.2.1 Serologic studies – We will evaluate pre- and post-vaccination serologic 
responses in both IIV4 and RIV4 groups.  IgG levels will be measured for the 

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specific viral strains included in the 2019-2020 and 2020-2021 quadrivalent 
influenza vaccines using hemagglutination inhibition assays at the Duke Regional 
Biocontainment Laboratory (RBL) Virology Unit. Venous blood (approximately 15 
mL of blood) will be collected from each participant before and 29 (-7 to +14) 
days after vaccination. At Duke, maternal and cord blood (approximately 15mL of 
blood each) collection will be performed at delivery for serological analysis in 
both RIV4 and IIV4 vaccination groups. At the other sites, these samples 
(maternal and cord blood) will be collected during delivery only if feasible for 
similar serological analysis.  An assessment of placental antibody transfer 
(maternal:cord antibody ratio) will be determined.   
   
3.2.2 Future studies - In addition to the specified analyses described thus far, there 
may be other tests or assays that have yet to be identified that may be important 
for interpreting our study findings or of relevance to maternal-infant health 
outcomes.  Therefore, participants will be offered, through an opt-in/opt-out 
strategy to allow for the storage of any remaining blood (serum/plasma) after all 
specified analyses have been completed.  Additional laboratory assays may test 
for antibodies against other bacteria or viruses, markers of inflammation, or used 
in research on the health of mothers and infants. Specimens banked for use in 
other studies will be linked to information (including identifying information) that 
participants provided to the study. Because it is unknown if future testing will be 
of any utility, results of future testing will not be provided.  
In addition, participants will be offered, again through an opt-in/opt-out strategy, 
to allow study staff to contact them in the future to take part in other research 
studies.    
 
4 STUDY ENROLLMENT AND WITHDRAWALS 
4.1  Participant Inclusion Criteria 
Participants who meet all of the following criteria will be eligible to participate in 
this interventional study.   
1. Pregnant, as determined by medical history 
2. Age ≥ 18 years of age at enrollment 
3. Intention of receiving influenza vaccine based on ACIP-CDC guidelines 
4. Willing to provide written informed consent prior to initiation of any study 
procedures 
5. Gestational age at vaccination < 34 weeks 0 days based on reconciliation of last 
menstrual period and ultrasound dating. Estimated due date (EDD) and 
Gestational Age (GA-EDD) will be based on reconciliation of “sure” first day of 
the last menstrual period (LMP) and earliest dating ultrasound.  If the LMP is 
uncertain, then the  
 
 
 
 
Table 1. Ultrasound Parameters for Using Sure LMP to Determine 
Gestational Age 
Gestational age at first 
ultrasound by LMP 
Ultrasound agreement with 
LMP 

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earliest dating ultrasound will be used to 
determine EDD and GA. If the ultrasound 
derived-EDD is in agreement with sure-
LMP derived EDD (Table 1),  
then the LMP-derived EDD is used to 
determine GA. If the ultrasound derived 
EDD is not in agreement with the LMP-
derived EDD, the ultrasound-derived EDD is used to determine GA. 
6. English or Spanish literate 
7. Intention of being available for entire study period and complete all relevant study 
procedures, including follow-up phone calls and collection of delivery information.   
 
4.2 Participant Exclusion Criteria 
Participants who meet any of the following criteria will not be eligible to 
participate in this study: 
1. Influenza vaccine receipt during 2019-2020 or 2020-2021 influenza season prior 
to study enrollment.  
2. Participation in this study in 2019-2020 influenza season 
3. Any condition that may interfere with assessment of local injection site reactions, 
e.g. obscuring tattoos  
4. Known or suspected immunosuppression as a result of an underlying illness or 
treatment 
5. Use of anti-cancer chemotherapy or radiation therapy within the preceding 36 
months 
6. Use of oral or parenteral corticosteroids (≥ 20mg/day prednisone equivalent) or 
high-dose inhaled glucocorticoid for ≥ 14 consecutive days within the preceding 
30 days  
7. Has an active neoplastic disease (excluding non-melanoma skin cancer), a 
history of any hematologic malignancy, current bleeding disorder, or taking 
anticoagulants (a daily aspirin is acceptable) 
8. Has a history of receiving immunoglobulin or other blood product (with exception 
of Rh immunoglobulin) within the 3 months prior to study vaccination. 
9. History of febrile illness (> 100.4°F or 38°C) within the past 24 hours prior to 
study vaccination 
10. Contraindication to IIV or RIV receipt including history of severe allergic reaction 
after a previous dose of any influenza vaccine; or to a vaccine component, 
including egg protein   
11. History of Guillain-Barré syndrome within 6 weeks of a prior dose of any 
influenza vaccine 
12. Receipt of any licensed vaccine within 7 days prior to study vaccination or 
intention of receiving any vaccines during 8-day post-vaccination period  
13. Receipt of live vaccine during current pregnancy 
14. Signs or symptoms of active preterm labor, defined as regular uterine 
contractions with cervical change (dilation/effacement) 
15. Known multi-fetal gestation or fetal congenital anomaly, e.g. genetic abnormality 
or major congenital malformation based on antenatal ultrasound  
16. Anyone who is already enrolled or plans to enroll in another randomized clinical 
trial with any drug, vaccine or medical device. Co-enrollment in observational or 
behavioral intervention studies are allowed at any time 
8 6/7 wk or less 
± 5 days 
9 0/7 wk to 13 6/7 wk 
± 7 days 
14 0/7 wk to 15 6/7 wk 
± 7 days 
16 0/7 wk to 21 6/7 wk 
± 10 days 
22 0/7 wk to 27 6/7 wk 
± 14 days 
28 0/7 wk and beyond 
± 21 days 

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17. Any condition which, in the opinion of the investigators, may pose a health risk 
to the participant or interfere with the evaluation of the study objectives.   
18. Anyone who is a relative of any research study personnel or is an employee 
supervised by study staff 
4.3 Recruitment 
Pregnant women at ≤ 34 weeks, ≥ 18 years old, who are planning to receive influenza 
vaccination during their current pregnancy will be recruited at prenatal clinics whose 
patients deliver at Duke University Hospital (Duke), University of Cincinnati Medical 
Center (Cincinnati), or Boston Medical Center (Boston). Pregnant women will be pre-
screened for eligibility via medical record review. The study will be introduced to a 
potential participant by a member of their care team. Potential participants that fall within 
the ≤ 34 weeks gestation range will be approached by a member of the research team 
for study enrollment. Medical and obstetric history, including prior influenza vaccine 
history, will be obtained via participant self-report with verification by chart review 
whenever feasible (including medical records, employee health records, immunization 
registry records, and pharmacy records).  
4.4 Reasons for and Handling of Withdrawals 
The following may be reason for study withdrawal: 
• 
As deemed necessary by the principal investigator (PI).  
• 
Participant withdrawal of consent. 
• 
Loss to follow-up. 
• 
Termination of the study by the sponsor. 
 
Participants may withdraw their consent for study participation at any time and for any 
reason, without penalty. Participants who withdraw from the study prior to receiving 
study vaccine will be replaced. Participants who withdraw from the study after receiving 
vaccine will not be replaced. Every attempt should be made to collect all data specified 
by the protocol, including collection of pregnancy outcome/safety data via medical record 
review for participants who request withdrawal from study interventions/procedures.   
4.5 Termination of Study  
This study may be terminated for safety concerns of the principal investigators from the 
Lead or Contributing sites, CDC, or participating IRBs.   
 
5 STUDY SCHEDULE, PROCEDURES, & EVALUATIONS 
5.1 Schedule of events 
Pregnant women meeting the proposed eligibility criteria will be recruited. Written 
informed consent (will be obtained from study participants prior to conducting any study 
procedures. Table 1 describes the proposed schedule of study visits with further details 
below.  
 
 

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 1Cord blood and maternal blood collection at Visit 6 will be optional and collected when feasible by the site.  
 
Screening Visit, Study Day -30 to 1 (Chart Abstraction & Clinic Visit – may occur 
simultaneously with Visit 1) 
• Obtain written informed consent and release of medical record information 
• Review and confirm study eligibility 
• Obtain information on preferred method of contact for follow-up (telephone or email 
reminder or text reminder) 
• Obtain demographic data  
• Obtain influenza vaccination history 
• Obtain medical history (e.g. chronic hypertension, diabetes, autoimmune disorder), 
obstetric history (e.g. parity, prior preterm birth, low birthweight, small for gestational 
age), and current pregnancy status (e.g. gestational diabetes, gestational 
hypertension, placenta previa, estimated due date)  
• Obtain concomitant medication use 
 
 
 
Table 1. Study Visit Schedule 
Procedure 
Screening 
Visit* 
Day -30 to 1 
Visit 1 
Day 1 
Visit 2 
Day 4 + 1 
Visit 3 
Day 9 + 3 
Visit 4 
Day  29     
-7/+14  
Visit 5 
Day 43 + 7 
Visit 6 
Delivery 
Visit 7 
Postnatal 
Day 90 + 14 
Unscheduled 
Visit 
 
Type of contact 
Chart 
Abstraction/ 
Clinic 
Clinic 
Phone/Text/
Email/Data 
Review 
Phone/Text
/Email/Data 
Review 
Clinic 
Phone/Text/
Email/Chart 
Abstraction 
Hospital/ 
Chart 
Abstraction 
Phone/Text/
Email/Chart 
Abstraction 
Clinic 
Informed consent & Medical 
Release of Information 
X 
 
 
 
 
 
 
 
 
Review Eligibility Criteria 
X 
X 
 
 
 
 
 
 
 
Demographic, Medical, and 
obstetric history 
X 
X 
 
 
 
 
 
 
 
Influenza Vaccination History 
X 
X 
 
 
 
 
 
 
 
Vital signs (temperature, blood 
pressure, and heart rate) 
 
X 
 
 
 
 
 
 
X 
Blood Sample Collection 
 
X 
 
 
X 
 
X1 
 
 
Randomization and 
Vaccination  
 
X 
 
 
 
 
 
 
 
Obtain immediate adverse 
event information 
 
X 
 
 
 
 
 
 
 
Dispense memory aid 
 
X 
 
 
 
 
 
 
 
Dispense study supplies 
 
X 
 
 
 
 
 
 
 
Complete Memory aid form 
(REDCap or paper) 
 
X 
X 
X 
 
 
 
 
 
Concomitant 
medications/vaccinations 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Obtain solicited adverse 
events 
 
X 
X 
X 
 
 
 
 
 
Obtain unsolicited adverse 
events 
 
X 
X 
X 
 
 
 
 
X 
Obtain serious adverse event 
information 
 
X 
X 
X 
X 
X 
X 
X 
X 
Infant data collection 
 
 
 
 
 
 
 
X 
 

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Visit 1, Study Day 1 - Screening, Enrollment, and Vaccination (Clinic Visit) 
• If Screening Visit occurred prior to Visit 1, review and confirm eligibility and all data 
collected during Screening Visit 
• Obtain vital signs including oral temperature prior to vaccination 
• Obtain 15mL (~2 tubes) blood sample prior to vaccination for serologic analysis  
• Randomize study participant to RIV4 or IIV4 
• Administer assigned study product – trained, licensed staff will serve as unblinded 
vaccinators to administer either RIV4 or IIV4 as described in Section A.4.3. Participants 
and all other study personnel involved in collection of memory aids, follow-up phone 
calls, data collection, etc. will be blinded to randomization arm.  
• Ensure participants receive the CDC Influenza Vaccine Information Statement  
(VIS) during the visit. 
• Observe participants for at least 20 minutes after vaccination and record any 
immediate adverse events (AEs)  
• Dispense oral thermometer, ruler (in order to standardize measurements) and 
memory aid. Review instructions for use of thermometer, ruler, and memory aid 
completion.   
• Participants will be given the choice of completing the memory aid electronically or 
on paper.  Participants who select the electronic method will enter their data into a 
REDCap web-based system 
• Confirm preferred method of contact for follow-up (telephone, email, or text 
reminder) 
• Confirm date of study Visit 4 (attempt to coincide with regularly scheduled prenatal 
visit as feasible) 
• Review concomitant medication use 
• Study staff will instruct participants to  
• 
Notify the study staff if they are hospitalized or have a severe adverse event 
• 
Follow up with their healthcare provider if they have any symptoms they find 
concerning 
• 
Notify study staff if they enroll in another research study 
 
Visit 2, Study Day 4 (window Days 3 – 5) Phone/Text/Email/Online Memory Aid 
review 
• 
Participants will complete their memory aid via paper or electronic entry from 
Day 1-8. 
• 
Participants using paper diary: 
o Study staff will contact participants using paper memory aid to collect 
and record memory aid data including AEs (solicited and unsolicited), 
serious AEs (SAEs), pregnancy status, and concomitant medications.  
o Participants will be  
 
Asked to notify the study staff if they are hospitalized or have a 
severe adverse event, 
 
Follow up with their healthcare if they have symptoms they find 
concerning 
 
Reminded that they will be contacted again between Day 9 and Day 
12 for Visit 3 
 
• 
Participants using REDCap web-based system: 

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o Study staff will review REDCap system to confirm data capture and 
assess for any AEs, SAEs, pregnancy status, and concomitant 
medications.   
o The study team will contact participants if they have any missing 
information. The study team may also contact participants if more 
information is needed to better describe AEs [including SAEs and severe 
(Grade 3) events] reported in the REDCap web-based system. 
o All participants using REDCAP web-based will be  
 
Reminded to continue data entry into REDCap web-based system 
 
Asked to notify the study staff if they are hospitalized or have a 
severe adverse event, 
 
Follow up with their healthcare provider if they have symptoms they 
find concerning 
 
Visit 3, Study Day 9 (window Days 9 – 12) Phone/Text/Email/Online Memory Aid 
Review 
• 
Participants will complete their memory aid via paper or electronic entry from 
Day 1-8.  
• 
Participants using paper diary: 
o Study staff will contact participants using paper memory aid to collect 
and record memory aid data including AEs (solicited and unsolicited), 
serious AEs (SAEs), and concomitant medications.  
o Remind participants to  
 
Notify the study staff if they are hospitalized or have a severe 
adverse event, 
Follow up with their healthcare if they have symptoms they find 
concerning 
o Confirm date of next scheduled study visit (attempt to coincide with 
regularly scheduled prenatal visit as feasible) 
 
• 
Participants using REDCap web-based system: 
o Study staff will review REDCap system to confirm data capture and 
assess for any AEs, SAEs, and concomitant medications.   
o The study team will contact participants if they have any missing 
information. The study team may also contact participants if more 
information is needed to better describe AEs [including SAEs and severe 
(Grade 3) events] reported in the REDCap web-based system. 
o All participants using REDCAP web-based will be  
Asked to notify the study staff if they are hospitalized or have a 
severe adverse event, 
 
Follow up with their healthcare if they have symptoms they find 
concerning 
 
Have their date for next scheduled study visit confirmed (attempt to 
coincide with regularly scheduled prenatal visit as feasible). 
   
Visit 4, Study Day 29 (window Days 21 – 42) Clinic Visit 
• Study staff will review the memory aid data (paper or electronic) and record any SAEs 
and concomitant medications 
• Obtain 15mL (~2 tubes) blood sample for serologic analysis 
• Confirm preferred method of contact for follow-up (telephone, email, or text 

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reminder) 
•  Remind participants   
o They will be contacted between Day 43 – 50 
o To notify the study staff if they enroll in another research study or 
are hospitalized 
o To follow up with their healthcare if they have symptoms they find 
concerning 
 
Visit 5, Study Day 43 (window Days 43 - 50) Phone Call/Text/Email Follow-Up/Chart 
Abstraction 
Study staff will contact study participants to record any SAEs and concomitant 
medications.  Medical records will be reviewed to obtain more information about any 
SAEs. Participants will be reminded that they may be contacted again after delivery and 
that they will be contacted ~ 90 days after delivery to obtain maternal and infant health 
data. 
 
Visit 6, Birth Outcomes Visit, Medical Record Review/Phone Call/ Hospital  
Study staff will screen the inpatient census for the study site Birthing Centers on a 
daily basis to identify study participants admitted for delivery. Medical records will 
be reviewed for maternal and infant outcomes as well as maternal Tdap receipt. At 
Duke, maternal and cord blood collection will be performed at delivery. At the other 
sites, these samples (maternal and cord blood) will be collected during delivery if 
feasible. Study participants who are not identified via review of inpatient census 
records will be contacted approximately 2 weeks after their estimated due date to 
determine if delivery occurred elsewhere. If so, maternal and infant medical records 
will be requested from the delivery hospital for data collection.  
For the pregnancy outcomes abortion (spontaneous or elective termination) or fetal 
death, medical records will also be reviewed. Study participants with these 
outcomes will be contacted only if more information is needed for data collection.  
 
Visit 7, Postnatal Day 90 (window Postnatal Days 90 - 104) Phone Call/Text/Email 
Follow-Up/Chart Abstraction 
Study staff will contact study participants to record any maternal or infant SAEs, including 
neonatal/infant death and re-hospitalization, and concomitant medications. Information will 
also be collected on emergency room visits and unanticipated visits to the primary care 
pediatrician or a specialist. Data will be verified via review of medical records.  Sites will 
have subjects sign medical records release forms for both themselves and their infants 
at the time of informed consent.   This is done so that in the event subjects and/or their 
infants are seen outside of the site’s medical coverages, that medical records regarding 
their emergency room or unanticipated visits can be requested.   
For neonatal deaths identified by the study team prior to Visit 7, study participants will 
contact participants only if more information is needed for data collection. 
 
*Unscheduled Visits 
• 
Obtain vital signs including oral temperature for the pregnant women  
• 
Record any solicited and unsolicited AEs through Day 8, maternal and infant 
SAEs and concomitant medications through 90 days after delivery 
• 
Confirm preferred method of contact for follow-up (telephone, email, or text 
reminder)  
 

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End of Study 
After unblinding, study participants will be given the opportunity to learn which vaccine 
they received. For interested participants, study staff will contact subjects with an IRB-
approved letter by either mail, email or patient portal message (e.g., MyChart) to inform 
them which vaccine they received. 
.  
Treatment Assignment Procedures 
This is a randomized, controlled, double-blinded study involving pregnant women who 
are to receive the influenza vaccine.  The designated vaccine brands for this study are 
Flublok® quadrivalent (Sanofi) and quadrivalent Flulaval® (GSK) (IIV4). However, the 
specific comparator IIV4 vaccine administered will be based on availability from 
manufacturers prior to the 2019-2020 and 2020-2021 influenza seasons. To the extent 
feasible, the same influenza vaccine brand will be used as the comparator vaccine 
during both influenza seasons at all recruiting sites. 
 
5.1.1 Randomization 
Participants will be randomized (1:1) to receive either RIV4 (Flublok® quadrivalent 
recombinant influenza vaccine) or IIV4 (quadrivalent inactivated influenza vaccine) using 
a permuted block randomization scheme stratified by study site (Duke, Cincinnati, 
Boston). The project statistician will generate permuted block randomization schemes 
which will be uploaded to REDCap (section 7.2.1). The randomization schedule will not 
be available to the study staff, so the next randomization allocation will not be known 
before randomization occurs. Following confirmation of study eligibility criteria during 
Visit 1, participant randomization will be through REDCap with treatment allocation 
recorded on the case report form (CRF). 
 
In the event that REDCap is unavailable, manual randomization will occur through the 
use of envelopes. The project statistician will prepare 20 envelopes per gestational age 
group per site (total of 40 per site) that will use the same randomization strategy as the 
primary scheme embedded in REDCap. When an unblinded team member is informed 
of the gestational age group, he/she will pull the next envelope in order. In order to 
capture the allocation per subject, a separate form in REDCap will be used by the 
unblinded personnel to add the assignment. A log will need to be kept at the site 
capturing these instances. 
 
5.1.2 Blinding 
This study is double-blinded, therefore study staff and participants will be blinded to 
randomization assignments.  Trained, licensed staff will serve as unblinded vaccinators 
to administer either RIV4 or IIV4.  All other study personnel involved in collection of memory 
aids, follow-up phone calls, and data collection, will be blinded to randomization arm.  
Laboratory staff will be blinded to randomization arm assignment.   
 
The participant will receive documentation of receipt of influenza vaccine without 
specification of whether it was RIV4 or IIV4 vaccine to preserve blinding.  In the event of 
individual participant clinical safety issues or overall study safety concerns, then blinding 
may be broken. 
 
5.1.3 Vaccine Supply, Storage, and Administration 
In order to ensure adherence to study randomization assignment, licensed RIV4 and 
IIV4 vaccines will be administered as study procedures. Licensed RIV4 and IIV4 will be 

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purchased for study administration and will be stored at 2° to 8°C in a research-specific 
medication refrigerator. While research staff maintain daily temperature logs for the 
medication refrigeration, it is also monitored 24/7 with alarm activation if out of range. 
Research staff are notified of any alarm activations and have an on-call system in place 
to report to the research center for further investigation. Flublok® quadrivalent (Sanofi) 
and quadrivalent Flulaval® (GSK) will be the designated study products.  
A single administration of both RIV4 and IIV4 comprises intramuscular delivery of 0.5mL 
total volume of each vaccine for adults. Unblinded, licensed providers will prepare the 
RIV4 or IIV4 by using opaque tape to cover the syringe before vaccine administration. 
Vaccine lot numbers will be recorded in the study accountability log available only to 
unblinded licensed staff or the investigational pharmacist. Dose and site of vaccine 
administration will be recorded by unblinded licensed staff. RIV4 and IIV4 will be 
administered in the deltoid of the patient’s preferred arm by an unblinded licensed 
provider. After administration, used study syringes will be disposed of according to 
standard operating procedure.  
 
A licensed provider who will be trained on the study protocol, will be present at the time 
of vaccine administration along with emergency management supplies available for 
initial treatment of an allergic reaction if needed. Additionally, a blinded post-assessment 
team will be present to assist study participants following vaccine administration; they 
will not be in the room at the time of vaccination.  
5.2 Reactogenicity and Safety Assessments 
Participants will be observed for at least 20 minutes post-vaccination and queried for any 
adverse events immediately following vaccination (e.g. wheezing, rash, dizziness, 
fainting) and recorded.  
Frequency and occurrence of local and systemic reactogenicity, unsolicited adverse 
events (AEs), serious AEs (SAEs), concomitant medication use, and unscheduled 
medical care will be assessed through post-vaccination Day 8 using a standard memory 
aid. At the time of study enrollment, participants will be given a thermometer and 
instructed on using the memory aid to document oral temperatures and post-vaccination 
symptoms. Beginning on the evening of Study Visit 1 (Day 1) following influenza 
vaccination, participants will record their oral temperature using the study-supplied 
thermometer for the next 8 days (Day 1 – 8). Temperature will be recorded at roughly 
the same time each day or when a participant feels feverish. If a temperature ≥ 100.4°F 
(38°C) is recorded, a second measurement will be taken. If more than one temperature 
is taken on the same day, the highest temperature should be recorded. Fever will be 
defined as a measured temperature ≥ 100.4°F (38°C).  Participants will classify local and 
other systemic reactogenicity events as mild, moderate, or severe as described in Table 
4 and 5. 
During Visits 2, 3, and 4 information reported by participants will be reviewed for 
accuracy and completion. Participants who report severe solicited adverse events or 
express any concern about symptoms/unsolicited events will be encouraged to follow up 
with their obstetrician or primary care provider. Study staff will assist with coordination of 
referral appointments as necessary. Medical records will be obtained and reviewed for 
any unscheduled medical appointment through post-vaccination Day 43.  
Table 4: Injection-site Reactogenicity* 
Symptom 
Mild (Grade 1) 
Moderate (Grade 2) 
Severe (Grade 3) 

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Table 5: System Reactogenicity* 
Systemic 
Mild (Grade 1) 
Moderate (Grade 2) 
Severe (Grade 3) 
Fever **  
≥100.4 to ≤101.1° F  
≥101.2 to ≤102.0° F  
≥102.1° F 
Malaise (Fatigue) 
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
Myalgia (Body 
aches) 
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
Arthralgia (Joint 
pain) 
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
Nausea 
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
Vomiting 
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
Diarrhea 
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
Abdominal pain 
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
Headache 
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
Chills/shivering  
Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism 
Prevents daily activity and resulted 
in medical visit or absenteeism  
** Oral temperature, no recent hot/cold beverages or smoking 
 
Administration of influenza vaccines including IIV and RIV is routine clinical care during 
pregnancy such that we do not anticipate having a significant issue with serious adverse 
events (SAEs). However, we will monitor study participants and their infants for SAEs 
during the protocol-defined surveillance period [i.e. from enrollment through 90 days 
postpartum].  
An SAE is defined as an AE that meets one of the following conditions: 
• Results in death (including SAB and fetal death) during the period of protocol-
defined surveillance  
• Is life-threatening (defined as immediate risk of death at the time of the event) 
• Requires inpatient hospitalization or prolonged hospitalization during the period of 
protocol-defined surveillance (other than routine hospital admission such as for labor 
& delivery)  
• Results in congenital anomaly or birth defect 
• Results in a persistent or significant disability/incapacity 
• Any other important medical event that may not result in death, be life threatening, or 
Pain  
Noticeable but does not 
interfere with activity  
Interferes with activity  but did not 
necessitate medical visit or absenteeism   
Prevents daily activity  and resulted in 
medical visit or absenteeism 
Tenderness  Noticeable but does not 
interfere with activity  
Interferes with activity but did not 
necessitate medical visit or absenteeism    
Prevents daily activity and resulted in 
medical visit or absenteeism 
Induration/  
Swelling 
25 to ≤50 mm  
51 to ≤100 mm   
>100 mm  
Erythema  
25 to ≤50 mm 
51 to ≤100 mm 
>100 mm 
*Injection-site criteria being used in the CISA Study on Safety of RIV4 versus IIV4  in Pregnant Women 

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require hospitalization, may be considered an SAE when, based upon appropriate 
medical judgment, the event may jeopardize the participant and may require medical 
or surgical intervention to prevent one of the outcomes listed above. Examples of 
such medical events include allergic bronchospasm requiring intensive treatment in 
an emergency room or at home, blood dyscrasias or convulsions that do not result in 
inpatient hospitalization, or the development of drug dependency or drug abuse. 
 
 
 
Reporting Adverse Events  
SAEs and unanticipated problems will be reported to the CDC and all participating 
IRBs according to institutional requirements.  Given that this study involves 
vaccines that are included as part of routine clinical care, there will not be a 
designated data safety monitoring board. If deemed necessary, we will designate an 
independent safety monitor with relevant expertise, in collaboration with the CDC. 
 
If indicated, adverse events (AEs) will be reported to the CDC’s Vaccine Adverse Event 
Reporting System (VAERS). The National Childhood Vaccine Injury Act requires 
healthcare providers to report:  
• 
Any adverse event listed by the vaccine manufacturer as a contraindication to 
further doses of the vaccine; or  
• 
Any adverse event listed in VAERS Table of Reportable Events following 
Vaccination (accessed at 
https://vaers.hhs.gov/docs/VAERS_Table_of_Reportable_Events_Following_Vaccinati
on.pdf )  that occurs within the specified time period after vaccination.  
 
In addition, CDC encourages reporting of any clinically significant adverse event that 
occurs in a patient. 
 
Study site investigators will assess relatedness to vaccine or study procedures (related, 
possibly related, unlikely related, or not related) for all AEs including SAEs. The study 
investigators will use their clinical judgement to make causality assessments and the 
final causality assessment decision is the responsibility of the site principal investigator 
where the subject was enrolled. 
 
5.3 Biospecimens Collection & Handling 
5.3.1 Serum   
Maternal and cord blood specimens will be collected during study visits as described in 
Table 1. All blood samples will be collected, processed, and frozen according to the 
standard operating procedures and not contain personal identifiers.  Serum aliquots will 
be frozen and stored at each site until planned laboratory analyses. 
The Study site(s) will process and ship these samples to Duke using standard 
procedures, in accordance with specimen transport policies. 
Any unused serum samples will be returned to the study site(s) after all assays have 
been completed.   
 

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6 LABORATORY ANALYSES 
6.1 Influenza Laboratory Analysis 
Flublok® quadrivalent (Sanofi) and quadrivalent Flulaval® (GSK) will be the designated 
study products. An alternate licensed IIV4 may be used in place of Flulaval® if there are 
unforeseen issues. 
As such, reference wild-type, reassortant, or vaccine virus strains representative of the 
specific viral antigens included in the 2019-2020 or 2020-2021 influenza vaccines will be 
used to evaluate the relative levels of all four influenza strain-specific antibodies in 
maternal serum (pre- and post-vaccination) and infant cord blood.  To accomplish these 
activities all patient samples will be interrogated for influenza antibodies against the 
strains of interest using the influenza hemagglutination inhibition assay (HAI).  This 
assay is considered the “gold-standard” measure by which to evaluate 
seroconversion/seroprotection in response to seasonal influenza vaccination. This assay 
will be performed in accordance with the Duke RBL Virology Unit’s fully optimized and 
approved SOP (RVUSOP004 Influenza HI of Serum Samples).  Briefly, test samples will 
be assayed by HAI as duplicate 2-fold dilution series starting at 1:10.  Serum dilutions 
are then incubated with a concentration of virus verified to possess a known potential for 
red blood cell (RBC) agglutination.  The presence of virus-specific antibodies is 
visualized via incubation of the virus-serum mixture with a RBC solution; the endpoint 
titer for a given dilution series is then expressed as the reciprocal of the final dilution in 
which complete HAI is observed.  By convention, seronegative samples are defined as 
having an endpoint HAI titer < 1:40 and seropositive samples as having an endpoint titer 
of ≥ 1:40; and seroconversion as a HAI titer ≥ 1:40 at day 29 if the baseline titer is < 1:10 
or a minimum four-fold rise in HAI titer if the baseline titer is ≥ 1:10 for each influenza 
vaccine antigen. 
 
7 STATISTICAL CONSIDERATIONS 
In collaboration with the Boston Medical Center, Cincinnati Children’s Hospital Medical 
Center, and CDC the research team at Duke will oversee the statistical analysis. Data 
will reside on a secure Duke server maintained by Duke Health Technology Solutions 
(DHTS).  For the study, a database will be developed and a data set for the study 
without personal identifiers will be made available to the CDC upon request.  Duke 
statisticians will develop a comprehensive Statistical Analysis Plan.  The summary points 
of the analysis plan are presented below. 
7.1 Definitions 
Pregnancy and birth outcomes in this study will be defined by the American College 
of Obstetrics and Gynecology’s REVITALIZE Obstetric Data Definitions16, CDC 
national Vital Statistic System17 or  World Health Organization18 if available.  
Definitions for the component of the primary outcome measures are as follows: 
• 
Preterm birth- born alive at less than 37 weeks and 0 days gestation 
• 
Spontaneous abortion (SAB)- pregnancy loss prior to 20 weeks 0 days 
• 
Fetal death- intrauterine death of fetus at or after 20 weeks 0 days 
• 
Neonatal death- infant death within first 28 days of life 
7.2 Sample Size and Power Estimation 
Allowing for a 5% drop out rate and given an initial N=430, there should be 
approximately 408 participants for evaluation. We assume that 15% of pregnant 
women will have adverse birth outcomes after vaccination with RIV4 or IIV4, based 

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on national and CISA site estimates of preterm birth rates.  We have selected a 
clinically meaningful noninferiority margin of 10%.  Statistical calculations show that 
with a one-sided alpha of 0.025 and 204 subjects in each group across all study 
sites, there is at least 80% power to reject the null hypothesis that RIV4 is noninferior 
to IIV4 in the proportion of adverse birth outcomes. 
 
7.3 Analysis Plan 
7.3.1 Study Populations – There will be three study populations the modified Intent-to-
treat (mITT), Per Proocol (PP), and Immunogenicity populations.  The mITT Population 
includes any participant that was enrolled, randomized into the study, and received 
vaccine. The PP Population is a subset of the ITT Population excluding those 
participants with major protocol violations. The Immunogenicity Population is a subset of 
the mITT Population that includes only subjects who received vaccine, provide baseline 
and Visit 4 blood draws available for analysis within the protocol-defined time frame, and 
with no protocol violations affecting immunogenicity.  These protocol violations will be 
listed in the Statistical Analysis Plan. Statistical analyses of the safety outcomes will be 
performed for both mITT and PP populations, and immunogenic outcomes will be 
analyzed for the Immunogenicity Population. 
 
7.3.2   Alpha Level - No adjustment to the alpha level will be made for the secondary and 
exploratory objectives. 
 
7.3.3   Primary Objective - To compare the proportions of adverse birth outcomes in 
pregnant women vaccinated with RIV4 versus IIV4.     
o Research hypothesis: The proportion of pregnant women with adverse birth 
outcomes will be non-inferior (not higher – based on the noninferiority margin) 
after receipt of RIV4 compared to IIV4. 
This objective will be assessed using a one-sided noninferiority test with the 
alpha level set at 0.025 (1-sided) and a noninferiority margin of 10%.   
The null hypothesis assumes that RIV4 is inferior to IIV4 in regards to the 
proportion of pregnant women with adverse birth outcomes. 
 
 
 
 
Ho: RIV4 - IIV4 ≥ 0.10 (10%) 
 
The alternative hypothesis states that RIV4 is noninferior to IIV4 in regards to 
the proportion of pregnant women with adverse birth outcomes. 
 
 
 
Ha: RIV4 - IIV4 < 0.10 (10%) 
 
The upper bound of a stratified (by study site) Newcombe binomial confidence 
interval (Yan and Su 2010) with Cochran-Mantel-Haenszel (CMH) weighting of 
the difference will be used to make this assessment. 
 
A composite outcome for adverse birth outcome [defined by the occurrence of 
at least one of the following events: preterm birth, spontaneous abortion, fetal 
death or neonatal death] will be used as the primary study endpoint.   

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7.3.4 Secondary Objective 1 - To compare proportions of preterm birth after RIV4 
versus IIV4 vaccination. This proportion will be compared between the RIV4 
group and the IIV4 group using an exact Mantel-Haenszel statistic (calculated in 
Proc Logistic in SAS) in a stratified analysis by site to control for the 
randomization blocks at the two-sided alpha 0.05 level.  The site adjusted relative 
risk and corresponding 95% confidence interval for the proportion of preterm birth 
will also be calculated.   
7.3.5    Secondary Objective 2 - To compare proportions of combined fetal death and 
neonatal death after RIV4 versus IIV4 vaccination. These proportions will be 
compared between the RIV4 group and the IIV4 group using an exact Mantel-
Haenszel statistic (calculated in Proc Logistic in SAS) in a stratified analysis by 
site to control for the randomization blocks at the two-sided alpha 0.05 level.  The 
site adjusted relative risk and corresponding 95% confidence interval for the 
proportions of combined fetal death and neonatal death will also be calculated. 
 
7.3.6    Secondary Objective 3 - To compare proportions of spontaneous abortion after 
RIV4 versus IIV4 vaccination. This proportion will be compared between the 
RIV4 group and the IIV4 group using an exact Mantel-Haenszel statistic 
(calculated in Proc Logistic in SAS) in a stratified analysis by site to control for 
the randomization blocks at the two-sided alpha 0.05 level.  The site adjusted 
relative risk and corresponding 95% confidence interval for the proportion of 
spontaneous abortion after vaccination will also be calculated. This will be a 
subgroup analysis of only those participants vaccinated at less than 20 weeks 
gestational age. 
 
7.3.7    Secondary Objective 4 - To compare proportions of moderate/severe solicited 
reactogenicity events in pregnant women vaccinated with RIV4 versus IIV4. 
Reactogenicity will be assessed for 8 days following the vaccination at Visit 1. 
These proportions will be presented by treatment group, symptom, and grade 
level (moderate/severe) for women with injection site reactogenicity within 8 days 
post-vaccination. These proportions will be compared between the RIV4 group 
and the IIV4 group, within symptom, using an exact Mantel-Haenszel statistic 
(calculated in Proc Logistic in SAS) in a stratified analysis by site to control for 
the randomization blocks at the two-sided alpha 0.05 level. Systemic 
reactogenicity will be presented in a similar fashion.  
 
7.3.8 Exploratory Objective 1: To compare and describe serious adverse events (SAE) 
in pregnant women vaccinated with RIV4 and IIV4. The proportion and 95% 
exact binomial confidence interval of serious adverse events (SAEs), as well as 
the total number of events, will be presented by site, vaccine group, severity, and 
relatedness.  Listings of these SAEs will also be presented.  Non-overlapping 
confidence boundaries will be an indication of a statistical difference between the 
groups. These presentations and listings will be provided for the participant’s 
study duration and for the first 42 days after vaccination. 
 

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7.3.9     Exploratory Objective 2: To compare proportions of adverse birth outcomes of 
clinical interest after RIV4 versus IIV4 vaccination. These proportions (i.e., 
infants born small-for-gestational age, pregnant women with clinical 
chorioamnionitis, and pregnant women with preeclampsia or eclampsia) will be 
compared between the RIV4 group and the IIV4 group using an exact Mantel-
Haenszel statistic (calculated in Proc Logistic in SAS) in a stratified analysis by 
site to control for the randomization blocks at the two-sided alpha 0.05 level.   
 
 
7.3.10 Exploratory Objective 3: To compare and describe health outcomes through 90 
days of life in infants born to women after RIV4 versus IIV4 vaccination. The 
proportion of infants with medically-attended events through 90 days of life and 
the proportion of infants with neonatal death will be compared between the RIV4 
group and the IIV4 group using an exact Mantel-Haenszel statistic (calculated in 
Proc Logistic in SAS) in a stratified analysis by site to control for the 
randomization blocks at the two-sided alpha 0.05 level. The proportion and 95% 
exact binomial confidence interval of SAEs in infants through 90 days of life, as 
well as the total number of events, will be presented by site, vaccine group, 
severity, and relatedness.  Listings of these SAEs will also be presented.  Non-
overlapping confidence boundaries will be an indication of a statistical difference 
between the groups. 
 
7.3.11 Exploratory Objective 4: To compare maternal immune responses to influenza 
antigens and calculate the post and pre-vaccination ratio after RIV4 versus IIV4 
vaccination. The proportion of pregnant women achieving seroconversion at day 
29 and the proportion pregnant women with a seroprotective HAI titer (≥ 1:40) 
pre- and post-immunization at day 29 will be compared using a Mantel-Haenszel 
statistic in a stratified analysis by site to control for the randomization blocks at 
the two-sided alpha 0.05 level. The geometric mean HAI titer (GMT) pre- and 
post-immunization at day 29 after RIV4 versus IIV4 vaccination for each 
influenza vaccine antigen will be compared (within vaccine arm pre versus post 
and within timeframe RIV4 versus IIV4) using a regression model with the log 
transformed titer value at the two-sided alpha 0.05 level.  
 
7.3.12 Exploratory Objective 5: To compare cord blood antibody levels for influenza 
antigens after RIV4 versus IIV4 vaccination. The proportion of infants with cord 
blood seroprotective HAI titer will be compared using a Mantel-Haenszel statistic 
in a stratified analysis by site to control for the randomization blocks at the two-
sided alpha 0.05 level. Infant cord blood geometric mean HAI titer (GMT) for 
each influenza vaccine antigen will be compared using a regression model with 
the log transformed titer value at the two-sided alpha 0.05 level. The ratio and 
95% confidence interval for cord blood to maternal influenza antibody titers at 
time of delivery for each influenza vaccine antigen after maternal RIV4 versus 
IIV4 vaccination will be presented. Non-overlapping confidence boundaries will 
be an indication of a statistical difference between the groups.  
 
7.3.13 Sensitivity analysis 
If there are any participants who receive the incorrect treatment (i.e., treatment 
other than what they were randomized to receive), then the primary and 

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secondary objectives will be analyzed based on the treatment the participant 
received not what the participant was randomized to receive. 
 
7.3.14 Interim Safety Data Review  
Given that this study involves administering U.S.-licensed vaccines 
recommended by the ACIP for use in pregnant women, and is included as part of 
routine clinical care, there will not be a designated data safety monitoring board 
for this study.  However, because RIV4 safety in pregnancy has not been 
systematically studied, an interim safety data review of all serious adverse events 
(SAEs) will be performed with the goal of identifying unexpected safety concerns 
of clinical importance. The safety data review will provide the study the 
opportunity to make changes to the protocol, if needed, prior to enrollment in the 
2020-2021 influenza season. The interim safety data review will be performed by 
an independent panel with relevant expertise who are not investigators on the 
study. The independent safety review panel will assess the clinical narratives of 
SAEs for all participants who were randomized and vaccinated in 2019-2020 
influenza season. If the CDC and study investigators determine additional 
analyses or reviews are needed, efforts will be made to conduct additional 
analyses or reviews that will not include analyzing the primary endpoint as a first 
step. This is to avoid introducing bias or increasing sample size needs for 
statistical power. 
 
7.3.16 Further analysis 
Prior to the second season of enrollment, randomization was stratified by 
gestational age (<20 weeks versus 20-34 weeks) and by site.  Stratification by 
gestational age was removed from Version 2.1 due to an error in the 
randomization schema noted after the first season.  The overall randomization to 
RIV4 vs IIV4 was maintained but the gestational age stratification was 
unbalanced due to the error. 
If the error in stratification by gestational age results in an imbalance in 
gestational age between the treatment groups, evaluation of secondary 
outcomes by treatment group will be done using gestational age as a covariate if 
specified analyses can adjust for this factor.  To have reasonable results, each 
cell count needs to be 5 or greater. 
 
7.4 
Data Management Plan 
The amount of data that will be collected for the proposed project will be substantial and 
will require a sophisticated, practical and flexible system that can accommodate different 
modes of data collection and several separate linked surveys. The novel Vanderbilt-
designed resource developed specifically for online collection of research information, 
the Research Electronic Data Capture (REDCap) platform, will be used to design study 
forms, including the reaction forms, and short customized questionnaires to collect 
information from study participants. This system will be used by Duke for data 
management.  All electronic linkages will fulfill regulations for protection of human 
participants and requirements to minimize the risk of breach of confidentiality. After initial 
set-up, the work load required for electronic data collection will be substantially reduced 
(description of REDCap resources below). Duke investigators have previously used the 
REDCap system for collection and analysis of large quantities of data. Participants will 

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be given the option to fill out their memory aid either directly in the REDCap system or 
on paper. All study-related documents containing protected health information, e.g. 
enrollment logs, case report forms, memory aids completed by study participants, will be 
maintained in secure research offices at Duke, which are accessible to research staff 
only.  
 
7.4.1 Research Electronic Data Capture (REDCap)  
Investigators within the NIH-funded Clinical and Translational Research Unit at 
Vanderbilt have developed REDCap (http://project-redcap.org/), to collect and manage 
data for diverse clinical and translational research studies. REDCap was designed 
around the concept of giving research teams an easy method to specify project needs 
and rapidly develop secure, web-based applications for collection, management and 
sharing of research data. REDCap accomplishes these key functions through use of a 
single study metadata table referenced by presentation-level operational modules. 
Based on this abstracted programming model, databases are developed in an efficient 
manner with little resource investment beyond the creation of a single data dictionary. 
The concept of metadata-driven application development is well established, and the 
critical factor for successful data collection lies in creating a simple workflow 
methodology allowing research teams to autonomously develop study-related metadata 
in an efficient manner.19 Of particular interest for this project, a subcomponent of 
REDCap, the REDCap Survey is designed for studies where data are collected directly 
from the research participant. This will be used with the web-based reaction forms that 
will be completed by the study participants.  Both products include secure institutional 
data hosting and include full audit-trails in compliance with HIPAA security requirements. 
The REDCap Consortium is comprised of 647 active institutional, including CCHMC. The 
REDCap currently supports 68,000 projects with over 89,000 users spanning numerous 
research focus areas across the consortium.  The current project will use this software 
application for the design of electronic forms to collect information from study 
participants, to link the baseline data, sample collection date, and laboratory results in an 
automated database family, to perform data cleaning and data quality assurance 
efficiently, and to design an analytical dataset for the analysis of the project data.  
 
Data will be entered directly into the REDCap database by members of the study team, 
from Duke, Cincinnati, and Boston. Study investigators will be responsible for assuring 
that all paper records are securely stored according to the requirements of their IRBs.  
The study investigators will be responsible for assuring the accuracy of the data entered 
from the paper forms into REDCap, as appropriate.  Only the assigned identifiers will be 
used in REDCap. Therefore, personal health identifiers will not appear in the REDCap 
database. 
 
In order to perform data cleaning and data quality assurance efficiently, numerous built-
in filters and checks for consistency of the data including range and limit checks, 
branching logic and pull down menus to limit choices for categorical variables to a pre-
specified list will be implemented and performed automatically to minimize data entry 
error. The data will be randomly sampled and checked against source records on a 
regular basis. The data and related analytical datasets will also be stored at the lead and 
contributing sites with secured password-protected computers. Coded data without 
personal identifiers will be made available to the CDC and transferred using a secure 
transfer method as described in Section 7.2.  
 

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7.4.2 Role of the CDC Investigators in the Project 
This study is funded by a CDC contract with Duke University, Cincinnati Children’s 
Hospital Medical Center and Boston University as Task Orders in the CISA Project 
Contract.  CDC staff will collaborate with the sites to develop the protocol, conduct the 
study, ensure the study is aligned with US Department of Health and Human Services 
(CDC) public health priorities, and analyze the data and disseminate the results. CDC 
may receive access to coded data not containing any directly identifying information.  
 
8 
   HUMAN PARTICIPANTS  
8.1 Human Participants Involvement, Characteristics, and Design 
Duke, Cincinnati, and Boston investigators will be responsible for submitting the 
protocol, informed consent, memory aids, recruitment materials and any written or 
verbally conveyed materials specific to this project to their institutional review boards.  
CDC staff will be responsible for submitting materials to the CDC for review and obtain 
reliance on Duke IRB.   
 
To facilitate participant recruitment at the practices, we will request a waiver of consent 
and HIPAA authorization for ascertainment (identification, selection) and/or recruitment 
of potential participants while recording identifiable private health information (PHI) prior 
to obtaining the participant’s consent.  This information will be obtained from review of 
the electronic scheduling and medical record systems in the clinics in order to determine 
eligibility for study enrollment. We will review information only the minimum amount of 
information necessary to determine eligibility, i.e. date of birth, current pregnancy status, 
pregnancy history, medical and surgical history, ultrasounds pertaining to current 
pregnancy, and recent laboratory test results. The PHI collected prior to consent will be 
used to recruit and screen only. Use of PHI in this manner involves no more than 
minimal risk to participants and no information will leave the study sites. 
 
Continuing reviews will be submitted to the IRBs in accordance with the new Common 
Rule.20  Protocol deviations or concerns about study integrity will be reported promptly to 
the overseeing IRB in accordance with institutional requirements. 
 
8.2 Sources of Material 
Medical history and immunization history will be obtained from the medical record and 
from patient report.  Demographic information will be obtained from the medical record 
and patient report.  Participants will record solicited adverse reactogenicity events and 
any medical intervention sought on the day of and 7 days following vaccinations on the 
memory aid. Memory aid information will be reported to the study team during a 
telephone call or in the web-based REDCap system. The research staff will assess one 
or more of the following:  weight, height, temperature, blood pressure, and pulse.   
8.3 Potential Risks and Benefits 
RIV4 and IIV4 are FDA licensed vaccines approved for use in pregnant women. IIV 
vaccines are standard clinical practice and recommended by the CDC and ACOG for 
women who are pregnant during the influenza season.  Participants will be provided with 
the CDC Vaccine Information Statement (VIS) for IIV and RIV.  
 
IIV and RIV risks include minor problems such as soreness, redness, swelling, or pain 
where the shot was given, hoarseness, sore, red or itchy eyes, cough, fever, aches, 

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headache, itching, fatigue, all of which usually occur within 1-2 days of vaccination and 
are self-limiting. Syncope (fainting) can occur in association with administration of 
injectable vaccines. More serious problems including a small increased risk of Guillain-
Barré Syndrome estimated at 1 or 2 additional cases per million people vaccinated. This 
is much lower than the risk of severe complications from influenza infection, which can 
be prevented by IIV or RIV.  (http://www.cdc.gov/vaccines/hcp/vis/vis-
statements/flu.html). 
 
Problems that could happen after any injected vaccine:  
• 
People sometimes faint after a medical procedure, including vaccination. Sitting 
or lying down for about 15 minutes can help prevent fainting, and injuries caused 
by a fall. Participants should inform their doctor should they feel dizzy, or have 
vision changes or ringing in the ears.  
• 
Some people get severe pain in the shoulder and have difficulty moving the arm 
where a shot was given. This happens very rarely.  
• 
Any medication can cause a severe allergic reaction. Such reactions from a 
vaccine are very rare, estimated at about 1 in a million doses, and would happen 
within a few minutes to a few hours after the vaccination. As with any medicine, 
there is a very remote chance of a vaccine causing a serious injury or death. 
 
Each maternal participant will be asked to have at least 2 blood samplings with the total 
volume not to exceed 30mL.  An optional blood sampling of an additional 15ml may 
occur during delivery.  Maternal participants may experience dizziness or fainting. There 
is no risk to the participant or their newborn for collection of cord blood, as the cord 
blood is drawn from the umbilical cord/placenta after the baby is not attached to it.  
 
The Advisory Committee on Immunization Practices (ACIP) and the American College of 
Obstetricians & Gynecologists (ACOG) recommend all women who will be pregnant 
during influenza season receive influenza vaccine. A licensed, recommended, and age-
appropriate IIV or RIV4 may be used.21 However, as with any influenza vaccines we 
cannot assure or guarantee protection against influenza given the potential for mismatch 
between circulating influenza vaccine strains and those included in seasonal influenza 
vaccines and variation in individual immune responses.   
 
There is the potential risk of loss of confidentiality about information obtained as part of 
this study. 
 
8.4 Adequacy of Protection Against Risks 
 
8.4.1 Protections against Risk 
Participants will be counseled on possible side effects following vaccination and followed 
closely during the first 8 days post-vaccination for assessment of local and systemic 
reactogenicity, solicited and unsolicited adverse events (AEs), serious AEs (SAEs), 
concomitant medication use, and unscheduled medical care. All participants will be 
monitored in a sitting or lying position for at least 20 minutes following vaccinations to 
help prevent fainting, and injuries caused by a fall. Participants with a prior history of any 
precaution or contraindication to either IIV or RIV will be excluded from study enrollment.  
Every effort possible will be made to keep information about participants confidential. 
Computerized participant information will be kept in password protected files on secured 
servers.  Paper case report forms will be kept in locked files belonging to the study 

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personnel.  Any publications resulting from this work will not contain any identifiable 
participant information. 
 
8.4.2 ClinicalTrials.gov Requirements 
The project is registered on ClinicalTrials.gov (NCT03969641). It is the responsibility of 
the lead site for creating, maintaining, and uploading pertinent information regarding the 
study as required by 45 CFR 46.116(h) to ClinicalTrials.gov.  The lead site will post their 
IRB-approved informed consent within the study’s record on ClinicalTrials.gov.   
Contributing sites will be responsible for providing the lead site with any changes to their 
site’s information as applicable.   
 
9.0 Human Participants 
In obtaining and documenting informed consent, the Investigator and study team will 
comply with the applicable regulatory requirements, Good Clinical Practices, and ethical 
principles. The written informed consent form must be signed and dated by the study 
participant prior to initiation of any study activities.   
 
9.1.1 Vulnerable Subjects Research 
Vulnerable subjects 
This study proposes to include pregnant women and neonates. 
 
Pregnant women 
RIV4 and IIV4 are FDA licensed vaccines and are recommended by the CDC and 
ACOG during pregnancy, however the risks for both vaccines are listed in section 8.3.   
 
The specific procedures to be performed as part of this study are limited to minimal 
blood draw (< 35mL over a 4-week period), and other non-invasive procedures that are 
commonly performed during routine physical exams and are considered safe for 
pregnant women.  These procedures do not pose greater than minimal risk to the fetus.  
 
This study will involve only those women who have given their free and informed 
consent in accordance with 45 CFR 46.116 and has the prospect of direct benefit to both 
the mother and infant. Randomization of vaccine administration provides minimal risk to 
the participant and fetus as IIV vaccines are routinely given during pregnancy and do not 
go beyond the scope of standard of care.  The small amount of blood that will be drawn 
during the duration of pregnancy (up to 30 ml) are considered safe and are not expected 
to cause any harm to the baby.  No inducement, monetary or otherwise, will be offered 
to terminate a pregnancy.  Individuals engaged in the research will have no part in any 
decisions as to the timing, method or procedures used to terminate a pregnancy, or in 
determining the viability of a neonate.   
 
Infants 
Identifiable private information will be collected about the infants at the time of delivery.  
Significant infant complications identified during the delivery visit will be followed up to 
90 days of life.    
 
Mothers will be informed about the infant data collection at the time they consent for the 
study, and thus, the consent form for pregnant women will also serve as the parental 
permission for including the infant as a participant after delivery.   
 

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REFERENCES 
1. 
Goodnight WH, Soper DE. Pneumonia in pregnancy. Crit Care Med 
2005;33:S390-7. 
2. 
Neuzil KM, Reed GW, Mitchel EF, Simonsen L, Griffin MR. Impact of influenza 
on acute cardiopulmonary hospitalizations in pregnant women. Am J Epidemiol 
1998;148:1094-102. 
3. 
Pierce M, Kurinczuk JJ, Spark P, Brocklehurst P, Knight M, Ukoss. Perinatal 
outcomes after maternal 2009/H1N1 infection: national cohort study. BMJ 
2011;342:d3214. 
4. 
Siston AM, Rasmussen SA, Honein MA, et al. Pandemic 2009 influenza A(H1N1) 
virus illness among pregnant women in the United States. JAMA 2010;303:1517-25. 
5. 
Committee on Obstetric P, Immunization Expert Work G, Centers for Disease C, 
Prevention's Advisory Committee on Immunization US, American College of O, 
Gynecologists. Committee opinion no. 608: influenza vaccination during pregnancy. 
Obstet Gynecol 2014;124:648-51. 
6. 
Grohskopf LA, Sokolow LZ, Broder KR, et al. Prevention and Control of Seasonal 
Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization 
Practices - United States, 2017-18 Influenza Season. MMWR Recomm Rep 2017;66:1-
20. 
7. 
Tamma PD, Ault KA, del Rio C, Steinhoff MC, Halsey NA, Omer SB. Safety of 
influenza vaccination during pregnancy. Am J Obstet Gynecol 2009;201:547-52. 
8. 
Haberg SE, Trogstad L, Gunnes N, et al. Risk of fetal death after pandemic 
influenza virus infection or vaccination. The New England journal of medicine 
2013;368:333-40. 
9. 
Madhi SA, Cutland CL, Kuwanda L, et al. Influenza vaccination of pregnant 
women and protection of their infants. The New England journal of medicine 
2014;371:918-31. 
10. 
Nordin JD, Kharbanda EO, Vazquez Benitez G, et al. Maternal influenza vaccine 
and risks for preterm or small for gestational age birth. J Pediatr 2014;164:1051-7 e2. 
11. 
Bratton KN, Wardle MT, Orenstein WA, Omer SB. Maternal influenza 
immunization and birth outcomes of stillbirth and spontaneous abortion: a systematic 
review and meta-analysis. Clin Infect Dis 2015;60:e11-9. 
12. 
McMillan M, Porritt K, Kralik D, Costi L, Marshall H. Influenza vaccination during 
pregnancy: a systematic review of fetal death, spontaneous abortion, and congenital 
malformation safety outcomes. Vaccine 2015;33:2108-17. 
13. 
Pandemic H. Influenza Plan. 2005. 
14. 
Vaccines Licensed for Use in the United States. 2019. (Accessed 16Apr2019, 
2019, at 
https://www.fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts/ucm093833.ht
m.) 
15. 
Skowronski DM, De Serres G. Role of Egg-adaptation Mutations in Low Influenza 
A(H3N2) Vaccine Effectiveness During the 2012-2013 Season. Clin Infect Dis 
2018;67:1474-6. 
16. 
Menard MK, Main EK, Currigan SM. Executive summary of the reVITALize 
initiative: standardizing obstetric data definitions. Obstetrics & Gynecology 
2014;124:150-3. 
17. 
Statistics NCfH. 2019. 
18. 
Organization WH. Preterm birth. 2018. 
19. 
Influenza activity--United States and worldwide, 2007-08 season. MMWR Morb 
Mortal Wkly Rep 2008;57:692-7. 

Safety of RIV4 versus IIV4 in Pregnancy 
 
Version 4.0 
March 15, 2022 
 
34 
20. 
Health UDo, Services H. Code of Federal Regulations, title 45, part 46. URL: 
http://www hhs gov/ohrp/archive/humansubjects/guidance/45cfr46 html 2009. 
21. 
Grohskopf LA, Sokolow LZ, Broder KR, Walter EB, Fry AM, Jernigan DB. 
Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the 
Advisory Committee on Immunization Practices-United States, 2018-19 Influenza 
Season. MMWR Recomm Rep 2018;67:1-20.