Overview
- CDC estimates about 11 million illnesses, 120,000 hospitalizations and 5,000 deaths so far this season, with outpatient visits for flu-like illness hitting the highest level in decades.
- Roughly 90% of H3N2 samples analyzed since September are the subclade K variant, which has spread widely without evidence it causes more severe disease than prior H3N2 strains.
- Hospitals and emergency departments report high patient volumes in multiple states, with local officials in places like Ohio and Florida noting long waits and very high flu activity.
- A preprint from the University of Pennsylvania finds this season’s vaccine boosts measurable antibodies against subclade K despite a partial mismatch, and the shot also covers circulating H1N1 and influenza B.
- Health authorities urge vaccination, early use of antivirals such as oseltamivir or baloxavir for eligible patients, and basic precautions, as some reports of federal guidance changes for children contrast with CDC materials that still advise shots for everyone 6 months and older.