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Influenza Virus Vaccine Plus Vitamin A and D Supplements for Prevention of Respiratory Virus Infections in Children

A Double-Blind, Randomized, Placebo-Controlled Study of Antibody Induction by Vitamin Supplementation at the Time of Influenza Virus Vaccinations in Children

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02649192
Enrollment
87
Registered
2016-01-07
Start date
2016-01-21
Completion date
2018-06-29
Last updated
2019-10-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Participants

Keywords

Children, Vitamin Supplements, Influenza virus vaccine

Brief summary

Children are particularly vulnerable to respiratory virus infections, especially influenza. Vitamin A & D deficiencies are associated with vulnerability to infectious diseases of the respiratory tract. The central hypothesis of this protocol is that vitamin supplements will enhance antibody responses toward the flu vaccine in children. Children, 2-8 years old, will be randomized to receive influenza virus vaccine with a vitamin A+D supplement or influenza virus vaccine with placebo. Children will be tested for vitamin levels and immune responses before and after influenza virus vaccinations to determine if vitamin supplementation improves the influenza virus vaccine-induced immune response. PRIMARY OBJECTIVE: * To assess the vaccine-induced and total antibody (including IgG and IgA) response after influenza virus vaccine administration and IgA/IgG plus IgA/IgM ratios at 28 and 56 days in sera SECONDARY OBJECTIVE: * To assess the neutralizing response toward influenza virus vaccine in the sera.

Detailed description

Participants will be randomized to receive either an influenza virus vaccine plus Vitamins A & D or an influenza virus vaccine plus placebo. They will be stratified based on retinol binding protein (RBP) levels at screening, using a cut-off indicative of Vitamin A insufficiency (≤22,000 ng/ml). Co-enrolled sibling participants will be first stratified by RBP levels, then siblings within the same stratum will be equally assigned to different arms to provide greater assurance of balanced treatment assignment. Children will be tested for vitamin levels and immune responses before and after influenza virus vaccinations to determine if vitamin supplementation improves the influenza virus vaccine-induced antibody immune response. All participants will receive two doses of an influenza virus vaccination administered at least 28 days apart. Vitamin levels and antibody responses toward the vaccine will be measured on day 0 (baseline levels obtained where day 0 equals the first influenza virus vaccination administration), day 28, and day 56. Placebo or Vitamins A + D (at the levels of 20,000 IU and 2,000 IU, respectively) will be administered orally on the days of vaccination. Blood serum samples will be collected from participants on Day 0, prior to receiving influenza virus vaccine on Day 28, and during their Day 56 follow-up visit. Parents will be asked to fill out diary cards to indicate food intake for children during the study period along with an optional food frequency questionnaire given on day 56. Specific measurements on days 28, and 56 will include analyses of vaccine-specific and total IgA, IgG, and IgA/IgG plus IgA/IgM ratios in sera. Functional activities of antibodies toward influenza vaccine will also be measured.

Interventions

Children will have the first influenza virus vaccine dose (dose 1) administered on day 0 of the trial, and the second dose (dose 2) administered 28 days later.

DIETARY_SUPPLEMENTVitamins A and D

The chewable gummy contains either Vitamin A (20,000 International Units) and Vitamin D3 (2,000 International Units), which should be fully chewed under supervision of study staff with documentation in the participant's research record and eMAR (electronic medical administration record). The chewable gummy should be administered prior to receiving influenza virus vaccination.

OTHERPlacebo

The chewable gummy matched placebo will be formulated with gelatin base and tangerine oil and match the Vitamin A and D in shape, taste, texture, and appearance. Gummies should be fully chewed under supervision of study staff with documentation in the participant's research record and eMAR (electronic medical administration record). The chewable gummy should be administered prior to receiving influenza virus vaccination.

Sponsors

St. Jude Children's Research Hospital
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
2 Years to 8 Years
Healthy volunteers
Yes

Inclusion criteria

* Resident of the Memphis area community. * Parent or legal guardian willing and able to give informed consent and comply with study requirements.

Exclusion criteria

* Current use of investigational or immunosuppressive drugs (e.g., steroids) at the time of enrollment. * Currently taking a daily (routine) vitamin A, D, or multivitamin. Note: participants who report occasional or sporadic vitamin use will be allowed to enroll. * History of lung disease, asthma, immunodeficiency, sickle cell disease, or any other serious underlying condition or disease in the opinion of the principal investigator. * Evidence of developmental delay or evolving neurological disorders at screening. Current use of antibiotics or antivirals at enrollment. * History of having a severe allergy to eggs or to any inactive ingredient in the influenza virus vaccine * History of a life-threatening reaction to influenza vaccinations * Currently wheezing at the time of enrollment * History of heart, kidney, or lung conditions * History of diabetes * Use of an anti-influenza medication (including amantadine, rimantadine, oseltamivir, and zanamivir) within 14 days prior to enrollment * Acute febrile \[\>100.0°F (37.8°C) oral\] illness or acute respiratory illness (e.g., cough or sore throat) within 3 days prior to enrollment * Previous receipt of current seasonal influenza vaccine

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Participants With Positive Responses in Virus-specific Antibody in SeraDay 56 after vaccinationThe percentage of 2X increases or conversion from undetectable to detectable response in virus-specific antibody toward any vaccine component after 2 immunizations in intervention and control groups will be reported.
Isotype Ratios on Day 56Day 56 after vaccinationIsotype ratios will be summarized with descriptive statistics.

Secondary

MeasureTime frameDescription
Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallDay 56 after vaccinationSecondary analyses will examine sero-conversion based on antibody functions (HAI or neutralization) defined as antibody titers of \<1:40 converting to ≥1:40, or a four-fold increase in titer for participants with a starting titer of ≥1:40. Sero-conversion rate (expressed as percentage) will be estimated with 95% confidence interval. The rate difference will be described with point estimate and 95% confidence interval.
Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningDay 56 after vaccinationSecondary analyses will examine sero-conversion based on antibody functions (HAI or neutralization) defined as antibody titers of \<1:40 converting to ≥1:40, or a four-fold increase in titer for participants with a starting titer of ≥1:40. Sero-conversion rate (expressed as percentage) will be estimated with 95% confidence interval for participants sufficient and insufficient in vitamin A at screening.
HAI Titers at Day 56 After Vaccination, OverallDay 56 after vaccination
HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningDay 56 after vaccination

Countries

United States

Participant flow

Participants by arm

ArmCount
A&D-S1
Participants receiving influenza virus vaccine plus vitamin A and D supplements in 2015-16 season
5
Placebo - S1
Participants receiving influenza virus vaccine plus matched placebo in 2015-16 season
4
A&D - S2
Participants receiving influenza virus vaccine plus vitamin A and D supplements in 2016-17 season
22
Placebo - S2
Participants receiving influenza virus vaccine plus matched placebo in 2016-17 season
22
A&D - S3
Participants receiving influenza virus vaccine plus vitamin A and D supplements in 2017-18 season
12
Placebo - S3
Participants receiving influenza virus vaccine plus matched placebo in 2017-18 season
14
Total79

Baseline characteristics

CharacteristicA&D-S1Placebo - S1A&D - S2Placebo - S2A&D - S3Placebo - S3Total
Age, Categorical
<=18 years
5 Participants4 Participants22 Participants22 Participants12 Participants14 Participants79 Participants
Age, Categorical
>=65 years
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Age, Categorical
Between 18 and 65 years
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Age, Continuous7 years3.5 years5 years4 years3 years5 years5 years
Ethnicity (NIH/OMB)
Ethnicity
Hispanic or Latino
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Ethnicity (NIH/OMB)
Ethnicity
Not Hispanic or Latino
5 Participants4 Participants21 Participants22 Participants12 Participants14 Participants78 Participants
Ethnicity (NIH/OMB)
Ethnicity
Unknown or Not Reported
0 Participants0 Participants1 Participants0 Participants0 Participants0 Participants1 Participants
Race/Ethnicity, Customized
Race
Black
5 Participants4 Participants15 Participants16 Participants8 Participants9 Participants57 Participants
Race/Ethnicity, Customized
Race
White
0 Participants0 Participants7 Participants6 Participants4 Participants5 Participants22 Participants
Region of Enrollment
United States
5 Participants4 Participants22 Participants22 Participants12 Participants14 Participants79 Participants
Sex: Female, Male
Female
3 Participants3 Participants14 Participants14 Participants6 Participants6 Participants46 Participants
Sex: Female, Male
Male
2 Participants1 Participants8 Participants8 Participants6 Participants8 Participants33 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
EG005
affected / at risk
deaths
Total, all-cause mortality
0 / 50 / 40 / 220 / 220 / 120 / 14
other
Total, other adverse events
5 / 52 / 46 / 226 / 224 / 123 / 14
serious
Total, serious adverse events
0 / 50 / 40 / 220 / 220 / 120 / 14

Outcome results

Primary

Isotype Ratios on Day 56

Isotype ratios will be summarized with descriptive statistics.

Time frame: Day 56 after vaccination

Population: Subjects with complete isotype data at day 56. Subjects with an undetermined assay result were not included in analyses. In some cases, the limit of detection (LOD) for the assay was reached and that LOD value was used in calculations.

ArmMeasureGroupValue (MEDIAN)
A&D - S1Isotype Ratios on Day 56IgA/IgM2.48 ratio
A&D - S1Isotype Ratios on Day 56IgA/IgG10.4 ratio
A&D - S1Isotype Ratios on Day 56IgA/IgG20.71 ratio
A&D - S1Isotype Ratios on Day 56IgA/IgG32.73 ratio
Placebo - S1Isotype Ratios on Day 56IgA/IgM1.37 ratio
Placebo - S1Isotype Ratios on Day 56IgA/IgG20.69 ratio
Placebo - S1Isotype Ratios on Day 56IgA/IgG10.3 ratio
Placebo - S1Isotype Ratios on Day 56IgA/IgG33.03 ratio
A&D - S2Isotype Ratios on Day 56IgA/IgG10.3 ratio
A&D - S2Isotype Ratios on Day 56IgA/IgM1.21 ratio
A&D - S2Isotype Ratios on Day 56IgA/IgG31.44 ratio
A&D - S2Isotype Ratios on Day 56IgA/IgG20.96 ratio
Placebo - S2Isotype Ratios on Day 56IgA/IgG10.27 ratio
Placebo - S2Isotype Ratios on Day 56IgA/IgM1.21 ratio
Placebo - S2Isotype Ratios on Day 56IgA/IgG31.68 ratio
Placebo - S2Isotype Ratios on Day 56IgA/IgG21.13 ratio
A&D - S3Isotype Ratios on Day 56IgA/IgG32.4 ratio
A&D - S3Isotype Ratios on Day 56IgA/IgM0.86 ratio
A&D - S3Isotype Ratios on Day 56IgA/IgG20.65 ratio
A&D - S3Isotype Ratios on Day 56IgA/IgG10.21 ratio
Placebo - S3Isotype Ratios on Day 56IgA/IgG10.28 ratio
Placebo - S3Isotype Ratios on Day 56IgA/IgM1 ratio
Placebo - S3Isotype Ratios on Day 56IgA/IgG20.75 ratio
Placebo - S3Isotype Ratios on Day 56IgA/IgG33.02 ratio
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG1 at day 56 in 2015-16 seasonp-value: 0.9Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG1 at day 56 in 2016-17 seasonp-value: 0.49Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG1 at day 56 in 2017-18 seasonp-value: 0.5Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG2 at day 56 in 2015-16 seasonp-value: 0.9Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG2 at day 56 in 2016-17 seasonp-value: 0.76Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG2 at day 56 in 2017-18 seasonp-value: 0.65Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG3 at day 56 in 2015-16 seasonp-value: 0.9Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG3 at day 56 in 2016-17 seasonp-value: 0.76Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgG3 at day 56 in 2017-18 seasonp-value: 0.54Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgM at day 56 in 2015-16 seasonp-value: 0.9Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgM at day 56 in 2016-17 seasonp-value: 0.95Wilcoxon (Mann-Whitney)
Comparison: Null hypothesis: No difference between intervention and placebo groups in the ratio of IgA/IgM at day 56 in 2017-18 seasonp-value: 0.34Wilcoxon (Mann-Whitney)
Primary

Percentage of Participants With Positive Responses in Virus-specific Antibody in Sera

The percentage of 2X increases or conversion from undetectable to detectable response in virus-specific antibody toward any vaccine component after 2 immunizations in intervention and control groups will be reported.

Time frame: Day 56 after vaccination

Population: All enrolled subjects who satisfied the inclusion/exclusion criteria were included in the analysis. For the four participants who didn't complete the study, results after one immunization were used.

ArmMeasureValue (NUMBER)
A&D - S1Percentage of Participants With Positive Responses in Virus-specific Antibody in Sera80 percentage of participants
Placebo - S1Percentage of Participants With Positive Responses in Virus-specific Antibody in Sera75 percentage of participants
A&D - S2Percentage of Participants With Positive Responses in Virus-specific Antibody in Sera100 percentage of participants
Placebo - S2Percentage of Participants With Positive Responses in Virus-specific Antibody in Sera100 percentage of participants
A&D - S3Percentage of Participants With Positive Responses in Virus-specific Antibody in Sera100 percentage of participants
Placebo - S3Percentage of Participants With Positive Responses in Virus-specific Antibody in Sera100 percentage of participants
Secondary

HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at Screening

Time frame: Day 56 after vaccination

Population: Subjects with complete HAI data at day 56. Subjects without a day 56 sample were not included in analyses.

ArmMeasureGroupValue (MEDIAN)
A&D - S1HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N15 titers
A&D - S1HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket42.5 titers
A&D - S1HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N2200 titers
A&D - S1HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
Placebo - S1HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N2720 titers
Placebo - S1HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
Placebo - S1HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket5 titers
Placebo - S1HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N15 titers
A&D - S2HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N1640 titers
A&D - S2HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
A&D - S2HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket5 titers
A&D - S2HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N21810 titers
Placebo - S2HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane40 titers
Placebo - S2HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N1640 titers
Placebo - S2HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N21280 titers
Placebo - S2HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket80 titers
A&D - S3HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket5 titers
A&D - S3HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane80 titers
A&D - S3HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N22560 titers
A&D - S3HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N11280 titers
Placebo - S3HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane80 titers
Placebo - S3HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N2320 titers
Placebo - S3HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N1640 titers
Placebo - S3HAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket5 titers
A&D-S1 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N15 titers
A&D-S1 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N2320 titers
A&D-S1 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
A&D-S1 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket5 titers
Placebo-S1 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N15 titers
Placebo-S1 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket5 titers
Placebo-S1 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N2480 titers
Placebo-S1 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
A&D-S2 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N1640 titers
A&D-S2 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N21545 titers
A&D-S2 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket5 titers
A&D-S2 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
Placebo-S2 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N1640 titers
Placebo-S2 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
Placebo-S2 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N2640 titers
Placebo-S2 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket5 titers
A&D-S3 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
A&D-S3 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N1640 titers
A&D-S3 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N2400 titers
A&D-S3 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket42.5 titers
Placebo-S3 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket42.5 titers
Placebo-S3 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N21920 titers
Placebo-S3 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N11920 titers
Placebo-S3 Non-VASHAI Titers at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane5 titers
Secondary

HAI Titers at Day 56 After Vaccination, Overall

Time frame: Day 56 after vaccination

Population: Subjects with complete HAI data at day 56. Subjects without a day 56 sample were not included in analyses.

ArmMeasureGroupValue (MEDIAN)
A&D - S1HAI Titers at Day 56 After Vaccination, OverallB/Brisbane5 titers
A&D - S1HAI Titers at Day 56 After Vaccination, OverallH3N2320 titers
A&D - S1HAI Titers at Day 56 After Vaccination, OverallH1N15 titers
A&D - S1HAI Titers at Day 56 After Vaccination, OverallB/Phuket5 titers
Placebo - S1HAI Titers at Day 56 After Vaccination, OverallB/Phuket5 titers
Placebo - S1HAI Titers at Day 56 After Vaccination, OverallH1N15 titers
Placebo - S1HAI Titers at Day 56 After Vaccination, OverallB/Brisbane5 titers
Placebo - S1HAI Titers at Day 56 After Vaccination, OverallH3N2480 titers
A&D - S2HAI Titers at Day 56 After Vaccination, OverallB/Brisbane5 titers
A&D - S2HAI Titers at Day 56 After Vaccination, OverallH1N1640 titers
A&D - S2HAI Titers at Day 56 After Vaccination, OverallH3N21810 titers
A&D - S2HAI Titers at Day 56 After Vaccination, OverallB/Phuket5 titers
Placebo - S2HAI Titers at Day 56 After Vaccination, OverallB/Phuket40 titers
Placebo - S2HAI Titers at Day 56 After Vaccination, OverallH3N21093 titers
Placebo - S2HAI Titers at Day 56 After Vaccination, OverallB/Brisbane40 titers
Placebo - S2HAI Titers at Day 56 After Vaccination, OverallH1N1640 titers
A&D - S3HAI Titers at Day 56 After Vaccination, OverallH3N2640 titers
A&D - S3HAI Titers at Day 56 After Vaccination, OverallH1N1905 titers
A&D - S3HAI Titers at Day 56 After Vaccination, OverallB/Phuket5 titers
A&D - S3HAI Titers at Day 56 After Vaccination, OverallB/Brisbane5 titers
Placebo - S3HAI Titers at Day 56 After Vaccination, OverallH3N2960 titers
Placebo - S3HAI Titers at Day 56 After Vaccination, OverallH1N11280 titers
Placebo - S3HAI Titers at Day 56 After Vaccination, OverallB/Brisbane42.5 titers
Placebo - S3HAI Titers at Day 56 After Vaccination, OverallB/Phuket5 titers
Secondary

Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at Screening

Secondary analyses will examine sero-conversion based on antibody functions (HAI or neutralization) defined as antibody titers of \<1:40 converting to ≥1:40, or a four-fold increase in titer for participants with a starting titer of ≥1:40. Sero-conversion rate (expressed as percentage) will be estimated with 95% confidence interval for participants sufficient and insufficient in vitamin A at screening.

Time frame: Day 56 after vaccination

Population: Subjects with complete HAI data at day 56. Subjects without a day 56 sample were not included in analyses.

ArmMeasureGroupValue (NUMBER)
A&D - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket0 percentage of participants
A&D - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N20 percentage of participants
A&D - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane0 percentage of participants
A&D - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N10 percentage of participants
Placebo - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N2100 percentage of participants
Placebo - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N10 percentage of participants
Placebo - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket0 percentage of participants
Placebo - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane0 percentage of participants
A&D - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N181.8 percentage of participants
A&D - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N272.7 percentage of participants
A&D - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket45.5 percentage of participants
A&D - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane36.4 percentage of participants
Placebo - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N1100 percentage of participants
Placebo - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane63.6 percentage of participants
Placebo - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N290.9 percentage of participants
Placebo - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket72.7 percentage of participants
A&D - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N271.4 percentage of participants
A&D - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane42.9 percentage of participants
A&D - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket42.9 percentage of participants
A&D - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N1100 percentage of participants
Placebo - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N187.5 percentage of participants
Placebo - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N237.5 percentage of participants
Placebo - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane50.0 percentage of participants
Placebo - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket25.0 percentage of participants
A&D-S1 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket0 percentage of participants
A&D-S1 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N10 percentage of participants
A&D-S1 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N266.7 percentage of participants
A&D-S1 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane0 percentage of participants
Placebo-S1 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N20 percentage of participants
Placebo-S1 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N10 percentage of participants
Placebo-S1 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane0 percentage of participants
Placebo-S1 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket0 percentage of participants
A&D-S2 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket10.0 percentage of participants
A&D-S2 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane20.0 percentage of participants
A&D-S2 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N270.0 percentage of participants
A&D-S2 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N160.0 percentage of participants
Placebo-S2 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N188.9 percentage of participants
Placebo-S2 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket33.3 percentage of participants
Placebo-S2 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N266.7 percentage of participants
Placebo-S2 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane44.4 percentage of participants
A&D-S3 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N275.0 percentage of participants
A&D-S3 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket50.0 percentage of participants
A&D-S3 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N125.0 percentage of participants
A&D-S3 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane0.0 percentage of participants
Placebo-S3 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH1N183.3 percentage of participants
Placebo-S3 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Phuket33.3 percentage of participants
Placebo-S3 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningH3N266.7 percentage of participants
Placebo-S3 Non-VASPercentage of Participants With Seroconversion at Day 56 After Vaccination, by Vitamin A Levels at ScreeningB/Brisbane16.7 percentage of participants
Secondary

Percentage of Participants With Seroconversion at Day 56 After Vaccination, Overall

Secondary analyses will examine sero-conversion based on antibody functions (HAI or neutralization) defined as antibody titers of \<1:40 converting to ≥1:40, or a four-fold increase in titer for participants with a starting titer of ≥1:40. Sero-conversion rate (expressed as percentage) will be estimated with 95% confidence interval. The rate difference will be described with point estimate and 95% confidence interval.

Time frame: Day 56 after vaccination

Population: Subjects with complete HAI data at day 56. Subjects without a day 56 sample were not included in analyses.

ArmMeasureGroupValue (NUMBER)
A&D - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH1N10 percentage of participants
A&D - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH3N240.0 percentage of participants
A&D - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Phuket0 percentage of participants
A&D - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Brisbane0 percentage of participants
Placebo - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Phuket0 percentage of participants
Placebo - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH3N250.0 percentage of participants
Placebo - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH1N10 percentage of participants
Placebo - S1Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Brisbane0 percentage of participants
A&D - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Brisbane28.6 percentage of participants
A&D - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Phuket28.6 percentage of participants
A&D - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH3N271.4 percentage of participants
A&D - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH1N171.4 percentage of participants
Placebo - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH1N195.0 percentage of participants
Placebo - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Brisbane55.0 percentage of participants
Placebo - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH3N280.0 percentage of participants
Placebo - S2Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Phuket55.0 percentage of participants
A&D - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Phuket45.5 percentage of participants
A&D - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Brisbane27.3 percentage of participants
A&D - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH3N272.7 percentage of participants
A&D - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH1N172.7 percentage of participants
Placebo - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH3N250.0 percentage of participants
Placebo - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Phuket28.6 percentage of participants
Placebo - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallB/Brisbane35.7 percentage of participants
Placebo - S3Percentage of Participants With Seroconversion at Day 56 After Vaccination, OverallH1N185.7 percentage of participants
Comparison: H1N195% CI: [0, 0]
Comparison: H1N195% CI: [-51.7, 6.2]
Comparison: H1N195% CI: [-49.4, 26.5]
Comparison: H3N295% CI: [-70.1, 56.1]
Comparison: H3N295% CI: [-38.8, 20.6]
Comparison: H3N295% CI: [-17.5, 57.9]
Comparison: B/Phuket95% CI: [0, 0]
Comparison: B/Phuket95% CI: [-54.1, 5.8]
Comparison: B/Phuket95% CI: [-23.1, 53.3]
Comparison: B/Brisbane95% CI: [0, 0]
Comparison: B/Brisbane95% CI: [-54.1, 5.8]
Comparison: B/Brisbane95% CI: [-45.4, 30.5]

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026