Massive study tests whether a stronger flu shot saves more seniors from hospitalization

NCT ID NCT06506812

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

Summary

This study combines data from two large trials in Denmark and Spain involving over 466,000 older adults. It compares the high-dose flu vaccine (Efluelda/Fluzone High-Dose) to the standard-dose flu shot to see which better prevents severe outcomes like hospitalization for flu or pneumonia. The goal is to get clearer answers by pooling data from different countries and seasons.

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 (Efluelda/Fluzone High-Dose Quadrivalent) vs. standard-dose quadrivalent influenza vaccine
What this could lead to
If high-dose vaccine proves more effective, it could become the preferred flu shot for older adults, reducing hospitalizations and deaths from flu.
What could go wrong
This is a pooled analysis of completed trials, not a new experiment. The results may not apply to all populations or flu seasons, and high-dose vaccine may cause more local reactions.

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

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

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

Contacts and locations

Locations

  • Center for Translational Cardiology and Pragmatic Randomized Trials, Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte

    Hellerup, Capital Region, 2900, Denmark

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