Overview
- The UK crossed the usual flu season threshold weeks early, with about 11% of tests positive in early November versus 3% a year ago, and 38% positivity among school-aged children.
- UKHSA data show H3N2 accounts for over 90% of typed influenza A cases, with influenza B circulating at very low levels.
- Preliminary UKHSA estimates indicate 70–75% protection against hospitalization in children aged 2–17 and roughly 30–40% protection in adults.
- Researchers describe the circulating H3N2 subclade as genetically drifted and mismatched to the vaccine component, with early analyses suggesting slightly higher transmissibility.
- NHS leaders warn of a difficult winter, while in the US early-season monitoring has been hampered by a shutdown-disrupted CDC surveillance system and officials urge vaccination and basic precautions.