17 December 2025 | Copenhagen
Influenza is sweeping across the European Region earlier than usual, with a newly dominant virus strain placing health systems under significant pressure in some countries. The public is recommended to take simple protective action to keep themselves and others safe this winter.
The influenza season has begun roughly 4 weeks earlier than in previous seasons. At least 27 of the 38 countries reporting data in the WHO European Region are now seeing high or very high influenza activity. In 6 countries – Ireland, Kyrgyzstan, Montenegro, Serbia, Slovenia and the United Kingdom – more than half of patients tested for influenza-like illness were positive for influenza.
“The flu comes around every winter, but this year is a little different,” said Dr Hans Henri P. Kluge, WHO Regional Director for Europe. “A new strain – A(H3N2) subclade K – is driving infections, though there is no evidence that it causes more severe disease. This new variant of seasonal flu now accounts for up to 90% of all confirmed influenza cases in the European Region. It shows how even a small genetic variation in the flu virus can place enormous pressure on our health systems because people do not have built-up immunity against it.”
While it may not prevent infection, early data from the United Kingdom confirm that the current seasonal influenza vaccine lowers the risk of severe health outcomes from A(H3N2) influenza virus. Vaccination remains the single most important preventive step to avoid severe health outcomes. This is especially important for those at higher risk, including older people, those with underlying conditions, pregnant women and children. In addition, health workers are also a priority group for vaccination to protect their own health and the health of their patients.
As in other seasons, school-aged children are the primary drivers of community spread. However, adults aged 65 and older constitute the majority of severe cases requiring hospitalization, highlighting their critical priority for vaccination.
How to stay safe this winter
Cases will continue to rise until the influenza season peaks, likely in late December or early January. Most people will recover from influenza on their own. People with severe symptoms or other medical conditions should seek medical care.
WHO reiterates proven measures to curb transmission and save lives.
- Get vaccinated. This is the best defence, especially for high-risk priority groups and health workers, who should also follow infection prevention measures and wear a mask when necessary.
- Stop the spread. Stay home if unwell. If you have respiratory symptoms, wear a mask in public to prevent passing the virus to others. When sneezing or coughing, cover your mouth and nose. Clean hands regularly. Open windows and doors frequently to improve air flow indoors.
“The current flu season, though serious, does not represent the level of global emergency we faced during the COVID-19 pandemic. Our health systems have decades of experience managing influenza, we have safe vaccines that are updated annually and we have a clear playbook of protective measures that work. If we use the proven tools that we already have – vaccination, health-conscious behaviour and strong public health systems to protect the most vulnerable – then we will weather this predictable, seasonal storm.”
“It is also vital in the current climate of mis- and disinformation to seek credible information from trusted sources like national health agencies and WHO,” concluded Dr Kluge. “In a challenging flu season, trustworthy evidence-based information can be life-saving.”