Influenza is spreading across Europe about a month earlier than usual this winter, driven by a newly dominant A(H3N2) strain, the World Health Organization said Wednesday.
At least 27 of 38 countries reporting data are seeing high or very high flu activity. In Ireland, Kyrgyzstan, Montenegro, Serbia, Slovenia and the United Kingdom, more than half of patients tested for influenza‑like illness were positive.
Hans Henri P. Kluge, WHO’s regional director for Europe, said the A(H3N2) subclade K now accounts for up to 90% of confirmed cases, though there is no evidence it causes more severe disease.
Early data from the UK suggest the seasonal flu vaccine reduces the risk of severe outcomes from A(H3N2), even if it does not always prevent infection. WHO urged vaccination, especially for older people, those with chronic conditions, pregnant women, children and health workers.
Cases are expected to rise until the season peaks in late December or early January. Most patients recover without treatment, but those with severe symptoms or underlying conditions should seek medical care, WHO said.