Understanding how older adults respond to influenza vaccines

A Deep Longitudinal Analysis of Next Generation Influenza Vaccines in Older Adults

PHASE4 · The Jackson Laboratory · NCT05518500

This study is testing how older adults respond to different flu vaccines to see if we can find ways to make the vaccines work better for them.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment75 (estimated)
Ages65 Years and up
SexAll
SponsorThe Jackson Laboratory (other)
Drugs / interventionschemotherapy, radiation, prednisone
Locations1 site (Farmington, Connecticut)
Trial IDNCT05518500 on ClinicalTrials.gov

What this trial studies

This prospective, single-arm study aims to investigate the mechanisms behind the diminished response to influenza vaccines in older adults. A cohort of 75 healthy individuals aged 65 and older will receive three different influenza vaccines over three consecutive flu seasons. Blood, nasal swab, and stool samples will be collected at various time points to analyze immune responses and identify biological pathways that could enhance vaccine efficacy. The findings are expected to inform future strategies for improving vaccine responses in this vulnerable population.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 65 years and older who have not received an influenza vaccine for the upcoming season.

Not a fit: Patients who have received any vaccine within two weeks prior to the flu vaccination may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved influenza vaccine efficacy and protection for older adults.

How similar studies have performed: Other studies have explored vaccine responses in older adults, but this specific longitudinal approach is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Able to speak and read English
* Male or Female, 65 years and older by date of enrollment
* Weight of 110 lbs or greater
* Has received influenza vaccine in the past seasons without severe adverse reactions
* Willing to receive an FDA-approved age-appropriate and CDC-recommended influenza vaccine for each of the 2022-23, 2023-24, and 2024-25 influenza seasons
* Willing to withhold all other vaccinations 2 weeks prior and 2 weeks after flu vaccination for the 2022-23, 2023-24, and 2024-25 influenza seasons
* Willing and available to participate in 19 study visits over three years around influenza vaccination
* Willing to provide blood samples at sixteen visits over three years
* Willing to agree to genomic testing of samples and sharing of de-identified genomic data generated from samples at the conclusion of the research

Exclusion Criteria:

* Received any vaccine (shingles, pneumococcal, COVID, etc.) within 2 weeks of anticipated flu vaccination for the 2022-23, 2023-24, and 2024-25 influenza seasons.
* Has already received an influenza vaccine for the approaching influenza season (2022-23)
* Has known allergy to eggs or any component of the flu vaccine. \[Although the Advisory Committee on Immunization Practices (ACIP) has concluded that a history of anaphylactic/anaphylactoid or severe allergic reaction to eggs should no longer be considered a contraindication to vaccination with any age-appropriate vaccine, for the purposes of this research study we elected to exclude individuals with these allergies\]
* History of Guillain-Barre syndrome (GBS)
* Body temperature greater than 100.3°F (38°C) on date of vaccination or within 2 days prior to vaccination by participant report (study entry may be delayed to meet this requirement)
* Rockwood Frailty Index score of \>0.21
* Known history of any of the following co-morbid conditions:

  * Chronic or recent (within past 2 months) infection requiring oral or intravenous antibiotics, antifungals, or antivirals
  * Cancer other than basal cell carcinoma requiring active surgical or medical treatment (chemotherapy or radiation therapy)
  * Congestive Heart Failure
  * Ischemic Heart Disease
  * Congenital abnormalities (PI to evaluate)
  * Paget's disease
  * Renal failure requiring ongoing dialysis
  * Chronic obstructive pulmonary disease, emphysema, or asthma
  * Severe autoimmune disease requiring biological therapy
  * Diabetes mellitus requiring insulin
  * Use of medicines during past 6 months known to alter immune response such as high-dose corticosteroids (≥ 10 mg/day of prednisone or equivalent)
  * HIV, AIDS or other immunodeficiency disorders
  * Recent (≤ 3 months) severe trauma or major surgery (PI to evaluate)
  * Current substance and/or alcohol abuse
* Patients currently residing in the Department of Correction
* Inability to comply with the protocol requirements
* Any other condition that, in the opinion of the PI, might interfere with study objectives

Where this trial is running

Farmington, Connecticut

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Aging, Influenza Vaccine, Dendritic Cell, Vaccine Response

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.