Systems Investigation of Vaccine Responses in Aging and Frailty

Systems Investigation of Vaccine Responses in Aging and Frailty (NCT05291676) is a Phase 2 interventional studying Influenza, sponsored by Yale University. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Influenza and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 96 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Influenza subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: - Age 21-40 or 65 and older - Ability to understand and give willing to sign a consent form (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 Who Should NOT Join This Trial: - 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. Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

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.

Treatments Being Tested

BIOLOGICAL

Fluzone

Fluzone High-Dose 0.7 ml intramuscular injection, standard as recommended by manufacturer

BIOLOGICAL

Fluad

Fluad Quadrivalent, MF59 adjuvanted 0.5 ml intramuscular injection, standard as recommended by manufacturer

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Yale School of Medicine

New Haven, Connecticut, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05291676), the sponsor (Yale University), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05291676 clinical trial studying?

This study will compare the immune response signatures (including immunologic, transcriptomic and metabolomic) of the two influenza vaccines approved for use in adults age 65 and over (Fluad and Fluzone High-Dose). The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT05291676?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05291676?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT05291676. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05291676. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.