Key Takeaways

Pfizer’s mRNA flu shot prevented more flu-like illness than a standard vaccine

More than 18,000 adults took part in the study

Side effects were mild and went away quickly

FRIDAY, Nov. 21, 2025 (HealthDay News) — Pfizer’s mRNA flu vaccine worked better than a standard flu shot in a large Phase 3 trial, researchers reported.

The results, published Nov. 19 in The New England Journal of Medicine , suggest that mRNA technology may help improve protection in future flu seasons.

The Pfizer flu vaccine uses the same type of messenger RNA science that was used in the company’s COVID-19 shot.

More than 18,000 adults took part in the Phase 3 trial during the 2022–2023 flu season. Some received Pfizer’s mRNA flu shot, while the others received Fluzone , a standar

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