Overview
- EU/EEA surveillance shows influenza detections rising 3–4 weeks earlier than in the past two seasons.
- ECDC identifies the A(H3N2) subclade K as the main driver of current circulation, representing about one-third of recent global A(H3N2) sequences and nearly half in the EU/EEA.
- Antigenic and serologic testing indicates a mismatch with the current northern-hemisphere A(H3N2) vaccine strain, and real-world effectiveness data are still limited.
- The agency urges eligible people to get vaccinated without delay and calls on health and long-term care facilities to reinforce preparedness, masking during high circulation, and timely antiviral use for high-risk patients.
- Regional data from Lombardy show 12.2% positivity in GP and pediatric testing and 11% in emergency departments compared with far lower rates in 2024, with 1.83 million flu vaccine doses administered by November 19.