Flu vaccine shows limited protection against evolving H3N2 strain

A Beijing study found that flu vaccination provided only moderate protection against a new H3N2 subclade circulating in late 2025, raising questions about vaccine effectiveness as the virus continues to mutate. The finding underscores growing challenges for health authorities and vaccine manufacturers in keeping pace with rapid viral evolution.

Originaltitel: Retraction note: Moderate protection from vaccination against influenza A(H3N2) subclade K in Beijing, China, September to December 2025 (Euro Surveill. 2026;31(2))