Military study aims to find the best flu shot

NCT ID NCT03734237

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.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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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.

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