CompletedPhase 4

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

United States23 participantsStarted 2024-05-21

Plain-language 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).

Who can participate

Age range

18 Years – 64 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * 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 Exclusion Criteria: * 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

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Magnitude of Antibody Response After the Late-season 2023 Vaccine

Timeframe: 0, 30, and 90 days after the 2023 vaccine

Magnitude of the Antibody Response After the 2024 Vaccine

Timeframe: Day 0, 30, and 90 after the 2024 vaccine

Trial details

NCT IDNCT06567860

SponsorLa Jolla Institute for Immunology

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2025-02-06

Results submitted2026-01-27

View on ClinicalTrials.gov More Influenza A trials