Clinical trial Recruiting at 1 site Observational Ages 9 to 64

Measuring flu vaccine immunity in COVID-19 patients

Official title: Understanding Immunity to the Flu Vaccine in COVID-19 Patients

Run by Stanford University · NCT04579588 · Data updated 2026-11-12

This study looks at how well the flu vaccine works in people aged 13 to 64 who have had COVID-19, comparing their immune responses to those who haven't had the virus.

Quick facts

Study typeObservational
Ages9 Years to 64 Years
SexAll
Enrollment230 (estimated)
SponsorStanford University
Academic / other
Locations1 site (Palo Alto, California)
StatusRecruiting
StartedOctober 29, 2020
Main results expectedApril 2028
Study endsApril 2028
Registry record updatedMarch 18, 2026
Trial IDNCT04579588 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates include adults and children aged 13 to 64 who have been diagnosed with COVID-19 at least two months prior to enrollment.

Probably not a fit

Patients who have received the influenza vaccine within the last four months or those with immunodeficiency or autoimmune diseases may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This observational study aims to assess the immunity response to the flu vaccine over time in individuals aged 13 to 64 who have previously been diagnosed with COVID-19. Participants will include both those with COVID-19 and a control group without the virus, allowing for a comparative analysis of immune responses. The study will focus on patients who may also have other medical conditions such as obesity, type 2 diabetes, chronic fatigue, or long-term COVID-19 symptoms. By monitoring these responses, the study seeks to understand how prior COVID-19 infection influences flu vaccine efficacy.

Why it matters

Potential benefit: If successful, this study could provide insights into optimizing flu vaccination strategies for COVID-19 survivors, potentially improving their immunity and health outcomes.

How similar studies have gone: While studies on vaccine responses in COVID-19 patients are emerging, this specific focus on flu vaccine immunity in this population is relatively novel.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age 9 through 64 years
* Diagnosed with COVID-19 at least 2 months prior enrollment
* Patients with or without obesity, diabetes, chronic fatigue and/or long term COVID-19 symptoms
* Patients without COVID-19 diagnosis for controls

Exclusion Criteria:

* Received the influenza vaccine less than 4 months ago
* Pregnant or lactating
* Patients with special risks attendant to venipuncture
* Use of immunomodulatory medications that may impact vaccine immune response per clinician's judgment
* Contraindication to the flu vaccine
* Immunodeficiency or autoimmune disease that may impact vaccine immune responses per clinician's judgement

Where it's running

  • Stanford University
    Palo Alto, California, United States
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 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.