Overview
- The World Health Organization recommended updating all three components for next season’s shots to target H1N1, H3N2 linked to subclade K, and the B/Victoria lineage.
- The guidance names A/Missouri/11/2025 for H1N1, A/Darwin/1454/2025 or A/Darwin/1415/2025 for H3N2, and B/Tokyo/EIS13-175/2025 or B/Pennsylvania/14/2025 depending on manufacturing method.
- An interim Canadian analysis estimated the current vaccine at 37% effectiveness against subclade K and 40% against H3N2 overall.
- This season’s surveillance shows unusually high hospitalizations alongside reduced vaccination uptake in several countries.
- The FDA’s vaccine advisory committee meets March 12 to weigh U.S. adoption, and WHO also requested candidate vaccine viruses for avian H9N2 as a precaution.