Super-Sized flu shot aims to better shield seniors

NCT ID NCT04498832

First seen Jun 25, 2026 · Last updated Jun 26, 2026 · Updated 1 time

Summary

This study tested a high-dose flu vaccine against a standard-dose one in 2,100 adults aged 60 and older in Japan. The goal was to see if the high-dose version triggers a stronger immune response. Participants received one shot and were followed for 28 days to measure antibody levels and safety.

What this could mean

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

Active substance

High-dose quadrivalent influenza vaccine (QIV-HD)

What this could lead to

If successful, this could provide better protection against flu for older adults, who are at higher risk of severe illness.

What could go wrong

This trial is complete, but results may not apply to other populations or flu seasons. A stronger immune response doesn't always mean fewer infections.

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

  • Investigational Site Number 3920001

    Osaka, Japan

  • Investigational Site Number 3920002

    Suita-Shi, Japan

  • Investigational Site Number 3920003

    Shinjuku-Ku, Japan

  • Investigational Site Number 3920004

    Koganeishi, Japan

  • Investigational Site Number 3920005

    Fukuoka, Japan

  • Investigational Site Number 3920006

    Kumamoto, Japan

  • Investigational Site Number 3920007

    Toshima-Ku, Japan

  • Investigational Site Number 3920008

    Shinjuku-Ku, Japan

  • Investigational Site Number 3920009

    Shinjuku-Ku, Japan

  • Investigational Site Number 3920010

    Yokohama, Japan