New mRNA flu shot passes first safety test in humans

NCT ID NCT05446740

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

Summary

This early-stage trial tested an experimental mRNA-based flu vaccine in 324 healthy younger (18-45) and older (60-80) adults. The main goal was to check safety and how well the vaccine triggers an immune response. Participants received one of several dose levels or a placebo, and researchers monitored side effects and antibody levels for about two months.

What this could mean

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

Active substance

mRNA-based influenza vaccine (GSK4382276A)

What this could lead to

If successful, this could lead to a new, more effective flu vaccine that uses mRNA technology, potentially offering better protection against influenza.

What could go wrong

This is an early Phase 1 trial with only 324 participants, so safety and immune response are still being tested. The vaccine may not work as hoped or could cause side effects.

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

  • GSK Investigational Site

    Edegem, 2650, Belgium

  • GSK Investigational Site

    Ghent, 9000, Belgium

  • GSK Investigational Site

    Halifax, Nova Scotia, B3J 3G9, Canada

  • GSK Investigational Site

    Sherbrooke, Quebec, J1L 0H8, Canada

  • GSK Investigational Site

    Madrid, 28006, Spain

  • GSK Investigational Site

    Madrid, 28046, Spain

  • GSK Investigational Site

    Madrid, 28222, Spain