UKHSA Health Protection Briefing Note: Influenza Early Season Activity

The UK Health Security Agency has published a Health Protection Briefing Note (2025/042) on influenza A(H3N2) early season activity in England and implications for clinical practice and laboratory referral. 

Influenza is circulating in the community approximately four weeks earlier than last year. ICUs are admitting a few cases across the UK and this usually increases over a 6-8 week period, then decreases over the same time period. Secondary bacterial infection, particularly with streptococcal and staphylococcal infection presenting with shock and multiple organ failure are likely to increase. This highlights the importance of vaccination and facilitating staff access to the influenza vaccination.