Home › COVID-19 and Coronavirus Infections › NCT04579588

Understanding Immunity to the Flu Vaccine in COVID-19 Patients

Who can join

Ages 9 to 64 · All sexes · Healthy volunteers welcome

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

About the study

The purpose of this study is to measure immunity to the flu vaccine over time in patients who have had COVID-19 and may have other medical conditions including obesity, type 2 diabetes, chronic fatigue, or long-term COVID-19 symptoms. Adults and children (age 9 to 64) who had been diagnosed with COVID-19 as well as controls without COVID-19 will be invited to participate in this study.

What is being tested

• Flu shot (biological)

Sponsor: Stanford University · Participants: 230 · Started: Oct 29, 2020

Contact the study team

• SNP Center Inquiry · Phone: (650) 521-7237

Official record on ClinicalTrials.gov — NCT04579588

Locations in the U.S.

Conditions

• COVID-19 and Coronavirus Infections
• Flu

From ClinicalTrials.gov, data retrieved Sep 29, 2026. Each study sets its own eligibility; the study team decides who can join.