Military study aims to find the best flu shot

NCT ID NCT03734237

Ongoing ⭐️ VACCINE ⭐️ Sponsor: Henry M. Jackson Foundation for the Advancement of Military Medicine Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This large study enrolled over 15,000 U.S. military members to compare three types of licensed flu vaccines: egg-based, recombinant, and cell-culture-based. Participants were randomly assigned to one of the three vaccines over four flu seasons. The main goal is to see which vaccine best prevents lab-confirmed flu. Results could help guide flu shot choices in the military.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: influenza vaccines (egg-based, recombinant, and cell-culture-based)
What this could lead to: If successful, this study could show which flu vaccine type is most effective for military personnel, helping to reduce flu illness in this population.
What could go wrong: This is a pragmatic trial, not a placebo-controlled one, so results may be influenced by real-world factors. Also, flu viruses change each year, so effectiveness may vary across seasons.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for INFLUENZA are added.

Our safety recommendation!

By submitting, you agree to our Terms of use

Conditions

The condition(s) this trial relates to.

influenza prevention target

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

INFLUENZA INFLUENZA -LIKE ILLNESS INFLUENZA VACCINES

Contacts and locations

Locations

Brooke Army Medical Center

Fort Sam Houston, Texas, 78234, United States
Lackland Airforce Base

San Antonio, Texas, 78243, United States
Madigan Army Medical Center

Tacoma, Washington, 98431, United States
Naval Medical Center Portsmouth

Portsmouth, Virginia, 23704, United States
Naval Medical Center San Diego

San Diego, California, 34800, United States
USU

Bethesda, Maryland, 20307, United States
United States Naval Academy

Annapolis, Maryland, 21402, United States
Walter Reed National Military Medical Center

Bethesda, Maryland, 20814, United States
Womack Army Medical Center

Fort Bragg, North Carolina, 28310, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.