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

NCT06567860 | Completed Phase 4 Results FDA Drug

• 1 other identifier: 286
• Study Type: interventional
• Target: 23
• Locations: 1 country
• Sites: 1

Brief 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

Influenza A

Keywords

Influenza vaccine; Immune response

Outcome Measures

Primary Outcomes (2)

• Magnitude of Antibody Response After the Late-season 2023 Vaccine

  The antibody response will be measured by hemagglutination inhibition (HAI) in adults between 18 and 64 years old who have not had an influenza vaccination prior to the study.

  0, 30, and 90 days after the 2023 vaccine

• Magnitude of the Antibody Response After the 2024 Vaccine

  The antibody response will be measured by hemagglutination inhibition (HAI) in adults between 18 and 64 years old who have not had an influenza vaccination prior to the study. This outcome was only performed on Arm 2.

  Day 0, 30, and 90 after the 2024 vaccine

Study Arms (1)

Late season influenza vaccine

EXPERIMENTAL

Every participant receives the 2023 influenza vaccine between May-June 2024, and then the 2024 influenza vaccine in September-October 2024. Blood draws are taken at Day 0, 30, and 90 post-vaccination.

Biological: Influenza Fluzone vaccine

Interventions

Influenza Fluzone vaccine BIOLOGICAL

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

Late season influenza vaccine

Eligibility Criteria

• Age: 18 Years - 64 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Be between 18-64 years of age
• Males or non-pregnant, non-nursing females
• Weigh at least 85 pounds for whole blood draw
• Ability to provide signed informed consent
• Subjects must plan to receive the intramuscular influenza vaccine at the La Jolla Institute for Immunology

You may not qualify if:

• Received an influenza vaccine in the past year
• Infection with human immunodeficiency virus, hepatitis B virus, or hepatitis C virus
• History of certain anemias
• Presence of significant cardiovascular disease, systemic diseases including, but not limited to, diabetes which is not controlled, renal disease, liver disease, malignancy, infection, or blood clotting disorder
• Inability to provide informed consent
• Recent whole blood donation within 56 days or leukapheresis within 112 days
• Children (under 18 years of age), elderly (65 years of age or older), pregnant or nursing females
• Individuals with egg allergies
• Has ever had Guillain-Barré syndrome

Sponsors & Collaborators

• La Jolla Institute for Immunology: lead

Study Sites (1)

La Jolla Institute for Immunology

La Jolla, California, 92037, United States

Location

MeSH Terms

Conditions

Influenza, Human

Condition Hierarchy (Ancestors)

Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases

Results Point of Contact

• Title: Tal Einav
• Organization: La Jolla Institute for Immunology

tal.einav@lji.org

(858) 752-6879

Study Officials

• Tal Einav, PhD

  La Jolla Institute for Immunology

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: August 20, 2024
• First Posted: August 23, 2024
• Study Start: May 21, 2024
• Primary Completion: February 6, 2025
• Study Completion: February 6, 2025
• Last Updated: February 12, 2026
• Results First Posted: February 12, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: ANALYTIC CODE
• Time Frame: Data will be available upon publication.
• Access Criteria: Data will be available with no restrictions.

Locations

US (1)