Comparing immune responses to two influenza vaccines in older adults

Systems Investigation of Vaccine Responses in Aging and Frailty

Phase 2 Interventional Yale University · NCT05291676

This study is testing whether a high-dose flu vaccine works better than a standard-dose flu vaccine for older adults living in nursing homes to help protect them from influenza.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment96 (estimated)
Ages21 Years and up
SexAll
SponsorYale University Academic / other
Locations1 site (New Haven, Connecticut)
Trial IDNCT05291676 on ClinicalTrials.gov

What this trial studies

This study compares the immune response signatures of two influenza vaccines approved for adults aged 65 and over: the high-dose Fluzone and the standard-dose Fluad. It aims to evaluate the innate and adaptive immune responses, as well as transcriptomic and proteomic signatures, in nursing home residents, who are particularly vulnerable to influenza. The study is randomized and open-label, including participants aged 21-30 as a control group. Participants will be monitored for influenza-like illness to assess the effectiveness of the vaccines.

Who should consider this trial

Good fit: Ideal candidates include adults aged 65 and older, particularly those residing in nursing homes, as well as younger adults aged 21-30 for comparison.

Not a fit: Patients with recent acute infections, those undergoing cancer treatment, or individuals with a history of severe allergic reactions to influenza vaccines may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved vaccination strategies for older adults, enhancing their immune response to influenza.

How similar studies have performed: Previous studies have shown significant immune responses to both high-dose and adjuvanted vaccines in older adults, indicating that this comparative approach is built on established findings.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age 21-40 or 65 and older
* Ability to understand and give informed consent (surrogate consent may apply to nursing home subjects who are decisionally impaired, with verbal assent to be obtained from subject)
* Plan to be in the New Haven, CT area for the next 4-6 weeks

Exclusion Criteria:

* Current use of medication, such as antibiotics in past two weeks. To clarify, patients taking antibiotics for the reason of a current acute infection will not be eligible. Those potential participants receiving antibiotics for prophylaxis purposes will be eligible to participate. The intention is not to create a separate group to drawn conclusions, but not to exclude these participants who are not acutely ill.
* Evidence of acute infection, identified by self- report of fever or symptoms in past two weeks
* Treatment for cancer in past three months.
* Previous adverse reaction to influenza vaccine requiring medical attention, such as allergic response (rash, anaphylaxis) or Guillain-Barré syndrome.
* Pregnant/possibly pregnant.
* History of organ, bone marrow or stem cell transplant, liver cirrhosis, kidney disease requiring dialysis, HIV/AIDS, hepatitis C or active hepatitis B
* Blood donation of 1 pint or more in past 2 months
* Treatment with clinical trial medication
* Presence of any other condition (e.g., geographical or social), actual or projected, that the investigator feels would restrict or limit the patient's participation for the duration of the study. This provision includes participants who have 50% or more missed appointments in the last three months.

Where this trial is running

New Haven, 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.
Conditions Influenzavaccineinfluenza vaccineolder adultsvaccine responsetoll-like receptorsimmune response
Last reviewed 2026-06-13 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.