Flu season surge tied to subclade K and vaccination gaps
The U.S. is facing a notably severe flu season, with most cases caused by influenza A(H3N2) subclade K. The strain’s mutations may reduce immunity from prior infections and vaccines, contributing to higher case counts and hospitalizations (CDC: about 15 million illnesses, 180,000 hospitalizations, 7,400 deaths so far). Vaccination rates are down—especially among children—amplifying spread, though vaccines still help and antivirals are effective when started early. Public health measures (masks, ventilation, staying home when sick) plus vaccination remain crucial.
