Trial Outcomes & Findings for Annual Study for Collection of Serum Samples in Children and Older Adults Receiving the 2020-2021 Formulations of Fluzone Quadrivalent Vaccine and Fluzone High-Dose Quadrivalent Vaccine, Respectively (NCT NCT04551677)

Last Updated: 2025-09-12

Results Overview

Blood samples were collected from participants at first vaccination at Visit 1 (Day 1; pre-vaccination) and at Day 28 after final vaccination either at Visit 2 (Visit 1 + 28 days) for participants who received 1 dose of influenza vaccine; or at Visit 3 (Visit 2 + 28 days) for participants who received 2 doses of influenza vaccine as recommended by ACIP. Collected blood samples were provided to Center for Biologics Evaluation and Research (CBER) for further analysis by World Health Organization (WHO), Centers for Disease Control and Prevention (CDC), and Food and Drug Administration (FDA) to support formulation recommendations for subsequent influenza vaccines.

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

90 participants

Primary outcome timeframe

Visit 1 (Day 1; pre-vaccination) and 28 days post-final vaccination at Visit 2/Visit 3

Results posted on

2025-09-12

Participant Flow

Participants were enrolled from 16 September 2020 to 10 October 2020 at 2 active sites in the United States.

A total of 90 participants were enrolled and vaccinated in the study.

Participant milestones

Participant milestones
Measure	Group 1: Fluzone Quadrivalent Influenza Vaccine: 6 to <36 Months Participants aged 6 to less than (\<) 36 months received a 0.5-milliliters (mL) dose of Fluzone Quadrivalent vaccine, intramuscularly, at Day 1. Participants for whom 2 doses of influenza vaccine were recommended per Advisory Committee on Immunization Practices (ACIP), a second dose was administered at Day 28.	Group 2: Fluzone Quadrivalent Influenza Vaccine: 3 to <9 Years Participants aged 3 to \<9 years received a 0.5-mL dose of Fluzone Quadrivalent vaccine, intramuscularly, at Day 1. Participants for whom 2 doses of influenza vaccine were recommended per ACIP, a second dose was administered at Day 28.	Group 3: Fluzone High-Dose Quadrivalent Influenza Vaccine: >=65 Years Participants aged greater than or equal to (\>=) 65 years received a 0.7-mL dose of Fluzone High-Dose Quadrivalent vaccine intramuscularly at Day 1.
Overall Study STARTED	29	31	30
Overall Study Vaccinated	29	31	30
Overall Study COMPLETED	29	31	30
Overall Study NOT COMPLETED	0	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Annual Study for Collection of Serum Samples in Children and Older Adults Receiving the 2020-2021 Formulations of Fluzone Quadrivalent Vaccine and Fluzone High-Dose Quadrivalent Vaccine, Respectively

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Group 1: Fluzone Quadrivalent Influenza Vaccine: 6 to <36 Months n=29 Participants Participants aged 6 to \<36 months received a 0.5-mL dose of Fluzone Quadrivalent vaccine, intramuscularly, at Day 1. Participants for whom 2 doses of influenza vaccine were recommended per ACIP, a second dose was administered at Day 28.	Group 2: Fluzone Quadrivalent Influenza Vaccine: 3 to <9 Years n=31 Participants Participants aged 3 to \<9 years received a 0.5-mL dose of Fluzone Quadrivalent vaccine, intramuscularly, at Day 1. Participants for whom 2 doses of influenza vaccine were recommended per ACIP, a second dose was administered at Day 28.	Group 3: Fluzone High-Dose Quadrivalent Influenza Vaccine: >=65 Years n=30 Participants Participants aged \>=65 years received a 0.7-mL dose of Fluzone High-Dose Quadrivalent vaccine intramuscularly at Day 1.	Total n=90 Participants Total of all reporting groups
Age, Categorical <=18 years	29 Participants n=93 Participants	31 Participants n=4 Participants	0 Participants n=27 Participants	60 Participants n=483 Participants
Age, Categorical Between 18 and 65 years	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Age, Categorical >=65 years	0 Participants n=93 Participants	0 Participants n=4 Participants	30 Participants n=27 Participants	30 Participants n=483 Participants
Age, Continuous	1.65 years STANDARD_DEVIATION 0.518 • n=93 Participants	5.13 years STANDARD_DEVIATION 1.75 • n=4 Participants	73.0 years STANDARD_DEVIATION 4.03 • n=27 Participants	26.6 years STANDARD_DEVIATION 33.1 • n=483 Participants
Sex: Female, Male Female	13 Participants n=93 Participants	12 Participants n=4 Participants	16 Participants n=27 Participants	41 Participants n=483 Participants
Sex: Female, Male Male	16 Participants n=93 Participants	19 Participants n=4 Participants	14 Participants n=27 Participants	49 Participants n=483 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Race (NIH/OMB) Asian	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Race (NIH/OMB) Black or African American	4 Participants n=93 Participants	1 Participants n=4 Participants	0 Participants n=27 Participants	5 Participants n=483 Participants
Race (NIH/OMB) White	23 Participants n=93 Participants	30 Participants n=4 Participants	30 Participants n=27 Participants	83 Participants n=483 Participants
Race (NIH/OMB) More than one race	2 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	2 Participants n=483 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants

PRIMARY outcome

Timeframe: Visit 1 (Day 1; pre-vaccination) and 28 days post-final vaccination at Visit 2/Visit 3

Population: Analysis was performed on all vaccinated participants i.e. the participants who had received at least 1 dose of the study vaccine. Here, 'number analyzed' = participants with available data for each specified category.

Outcome measures

Outcome measures
Measure	Group 1: Fluzone Quadrivalent Influenza Vaccine: 6 to <36 Months n=29 Participants Participants aged 6 to \<36 months received a 0.5-mL dose of Fluzone Quadrivalent vaccine, intramuscularly, at Day 1. Participants for whom 2 doses of influenza vaccine were recommended per ACIP, a second dose was administered at Day 28.	Group 2: Fluzone Quadrivalent Influenza Vaccine: 3 to <9 Years n=31 Participants Participants aged 3 to \<9 years received a 0.5-mL dose of Fluzone Quadrivalent vaccine, intramuscularly, at Day 1. Participants for whom 2 doses of influenza vaccine were recommended per ACIP, a second dose was administered at Day 28.
Number of Participants Aged 6 Months to <9 Years Who Provided Serum Samples for Analysis: Groups 1 and 2 Visit 1	29 Participants	31 Participants
Number of Participants Aged 6 Months to <9 Years Who Provided Serum Samples for Analysis: Groups 1 and 2 Visit 2	15 Participants	30 Participants
Number of Participants Aged 6 Months to <9 Years Who Provided Serum Samples for Analysis: Groups 1 and 2 Visit 3	14 Participants	1 Participants

PRIMARY outcome

Timeframe: Visit 1 (Day 1; pre-vaccination) and 21 days post-vaccination (Visit 2)

Population: Analysis was performed on all vaccinated participants.

Blood samples were collected from participants at first vaccination at Visit 1 (Day 1; pre-vaccination) and 21 days after vaccination (Visit 2). Collected blood samples were provided to CBER for further analysis by WHO, CDC, and FDA to support formulation recommendations for subsequent influenza vaccines.

Outcome measures

Outcome measures
Measure	Group 1: Fluzone Quadrivalent Influenza Vaccine: 6 to <36 Months n=30 Participants Participants aged 6 to \<36 months received a 0.5-mL dose of Fluzone Quadrivalent vaccine, intramuscularly, at Day 1. Participants for whom 2 doses of influenza vaccine were recommended per ACIP, a second dose was administered at Day 28.	Group 2: Fluzone Quadrivalent Influenza Vaccine: 3 to <9 Years Participants aged 3 to \<9 years received a 0.5-mL dose of Fluzone Quadrivalent vaccine, intramuscularly, at Day 1. Participants for whom 2 doses of influenza vaccine were recommended per ACIP, a second dose was administered at Day 28.
Number of Participants Aged >=65 Years Who Provided Serum Samples for Analysis: Group 3 Visit 1	30 Participants	—
Number of Participants Aged >=65 Years Who Provided Serum Samples for Analysis: Group 3 Visit 2	30 Participants	—

Adverse Events

Group 1: Fluzone Quadrivalent Influenza Vaccine: 6 to <36 Months

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Group 2: Fluzone Quadrivalent Influenza Vaccine: 3 to <9 Years

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Group 3: Fluzone High-Dose Quadrivalent Influenza Vaccine: >=65 Years

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Trial Transparency Team

Sanofi Pasteur

Phone: 800-633-1610

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee The Sponsor must have the opportunity to review at least 60 days prior to submission for publication or presentation. If review indicates that potentially patentable participant matter would be disclosed, publication or public disclosure may be delayed for a maximum of an additional 60 days to allow for filing the necessary patent applications.
Publication restrictions are in place

Restriction type: OTHER