He European Center for Disease Prevention and Control has issued an alert before a season of flu which spreads “unusually early” in the EU/EEA. The ECDC has assessed the risk of influenza in the context of the increasing circulation of a derived strain, recommending vaccination “without delay”.
A new variant
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Early virus circulation is being driven by influenza A(H3N2) specifically a new variant known as A(H3N2) subclade K (previously J.2.4.1). This subclade K has already been detected on all continents and represents almost half (47%) of all A(H3N2) sequences.
The analysis shows a significant divergence of subclade K with respect to the A(H3N2) vaccine strain used in the northern hemisphere. This is due to a number of mutations substantially higher than what was observed in evolutions of previous seasons. ECDC assesses the risk of the 2025/2026 flu season as moderate. Although the probability of infection is highFor most people, influenza is a self-limiting or even asymptomatic disease.
High risk groups
The risk is considered alto. It includes people over 65 years of age, people with chronic diseases (metabolic, pulmonary, cardiovascular, etc.), immunosuppressed people and pregnant people. The main concern is that while the individual risk of severe disease could be similar to previous years, a larger epidemic—driven by lower population immunity to A(H3N2) and the potential for vaccine mismatch—could result in a highest absolute number of hospitalizations and increase pressure on health services.
Vaccination immediately
The ECDC emphasizes that vaccination remains a vital public health tool. People eligible for vaccination, especially those at higher risk of severe disease, are advised to get vaccinated immediately. The vaccine is expected to continue offering protection against serious illness, even if the A(H3N2) virus is not well adapted. He early treatment with antivirals It is essential, especially for high-risk groups, as it can reduce the likelihood of complications. This is even more crucial in the face of a strain that may not completely match the vaccine.
Recommendations for hospitals
Hospitals and long-term care facilities are encouraged to review your preparation plansimprove infection prevention and control practices and implement the use of masks by staff and visitors during periods of high circulation of respiratory viruses.