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Characterizing Late-season Influenza Vaccine Responses to Compare the 2023 and 2024 Vaccine Formulations

NCT06567860 · Status: COMPLETED · Phase: PHASE4 · Type: INTERVENTIONAL · Enrollment: 23

Last updated 2026-02-12

Study results available
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Summary

Every 1-2 years, the seasonal influenza vaccine composition changes to include updated viruses, yet the precise effects of updating the vaccine remain understudied. Since the vaccine formulation for each season (with a season defined as starting in July and ending the following June) expires on June 30, vaccine formulations cannot be compared head-to-head. Thus, the 2023 and 2024 vaccines have only been compared by analyzing people given the former vaccine in the fall of 2023 and people given the latter vaccine in the fall of 2024, and baseline repertoires may have greatly changed over the course of that year. To that end, the investigators will vaccinate a cohort with the 2023 influenza vaccine between May-June 2024, in order to compare responses between individuals receiving the 2023 vaccine last fall, the 2023 vaccine late in the season (this cohort), and the 2024 vaccine next fall. The investigators will further assess whether the late-season 2023 vaccine primed this cohort to respond better to the standard 2024 vaccine with standard timing (vaccine administered around September-October).

Conditions

Interventions

BIOLOGICAL

Influenza Fluzone vaccine

Fluzone vaccine administered in both May-June and in September-October for each participant.

Sponsors & Collaborators

  • La Jolla Institute for Immunology

    lead OTHER

Principal Investigators

  • Tal Einav, PhD · La Jolla Institute for Immunology

Study Design

Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
18 Years
Max Age
64 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2024-05-21
Primary Completion
2025-02-06
Completion
2025-02-06
FDA Drug
Yes

Countries

  • United States

Study Locations

More Related Trials

Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT06567860 on ClinicalTrials.gov