The early arrival of seasonal influenza has continued sweeping across Europe, with at least 27 European countries reporting “high or very high” flu activity as of Wednesday.
In six countries – Ireland, Kyrgyzstan, Montenegro, Serbia, Slovenia, and the UK – more than one in two patients with influenza-like symptoms tested positive for the virus, according to the World Health Organisation (WHO)
The UN agency confirmed that a new influenza variant called A (H3N2) now accounts for up to 90 per cent of all confirmed cases in the European region.
“It shows how just a small genetic variation in the flu virus can place enormous pressure on our health systems because people don’t have built-up immunity against it,” Dr Hans Kluge, WHO Regional Director for Europe, said.
He also emphasised the importance of getting vaccinated quickly.
As in previous episodes of influenza, school-aged children are the primary drivers of community spread. But adults aged at least 65 are usually most at risk, constituting the majority of severe cases that require hospitalisation.
WHO had briefed reporters on Tuesday, warning that a new variant of influenza virus was rapidly gaining ground but expressed hope that vaccination remained the “most effective defence.
Dr Wenqing Zhang, Unit Head for Global Respiratory Threats at the Department of Epidemic and Pandemic Threats Management of WHO, said that 2025 was marked by “the emergence and the rapid expansion of a new AH3N2 virus subclade”.
The new variant – called J.2.4.1 or subclade K – was first noted in August in Australia and New Zealand and had since been detected in more than 30 countries,” she said.
“Current epidemiological data do not indicate an increase in disease severity, although this genetic shift makes a notable evolution in the virus,” Zhang said.
Influenza viruses are constantly evolving, she explained, which is why the composition of the influenza vaccine is regularly updated.
“WHO tracks these changes, assesses associated risks to public health and makes vaccine composition recommendations twice a year, through a longstanding global system – the Global Influenza Surveillance and Response System (GISRS), in collaboration with other global experts.
The new variant has not been incorporated, and is not part of the composition of the latest vaccines produced for the Northern Hemisphere influenza season, the WHO expert explained.
Still, “early evidence suggests that current seasonal vaccines continue to offer protection against severe diseases and reduce the risk of hospitalisation,” she said.
WHO estimates that there are around one billion cases of seasonal influenza annually, including up to five million cases of severe respiratory illness.
It added that up to 650,000 deaths each year are due to seasonal influenza-related respiratory disease.
New influenza strain circulates in Europe – WHO
The early arrival of seasonal influenza has continued sweeping across Europe, with at least 27 European countries reporting “high or very high” flu activity as of Wednesday.
In six countries – Ireland, Kyrgyzstan, Montenegro, Serbia, Slovenia, and the UK – more than one in two patients with influenza-like symptoms tested positive for the virus, according to the World Health Organisation (WHO)
The UN agency confirmed that a new influenza variant called A (H3N2) now accounts for up to 90 per cent of all confirmed cases in the European region.
“It shows how just a small genetic variation in the flu virus can place enormous pressure on our health systems because people don’t have built-up immunity against it,” Dr Hans Kluge, WHO Regional Director for Europe, said.
He also emphasised the importance of getting vaccinated quickly.
As in previous episodes of influenza, school-aged children are the primary drivers of community spread. But adults aged at least 65 are usually most at risk, constituting the majority of severe cases that require hospitalisation.
WHO had briefed reporters on Tuesday, warning that a new variant of influenza virus was rapidly gaining ground but expressed hope that vaccination remained the “most effective defence.
Dr Wenqing Zhang, Unit Head for Global Respiratory Threats at the Department of Epidemic and Pandemic Threats Management of WHO, said that 2025 was marked by “the emergence and the rapid expansion of a new AH3N2 virus subclade”.
The new variant – called J.2.4.1 or subclade K – was first noted in August in Australia and New Zealand and had since been detected in more than 30 countries,” she said.
“Current epidemiological data do not indicate an increase in disease severity, although this genetic shift makes a notable evolution in the virus,” Zhang said.
Influenza viruses are constantly evolving, she explained, which is why the composition of the influenza vaccine is regularly updated.
“WHO tracks these changes, assesses associated risks to public health and makes vaccine composition recommendations twice a year, through a longstanding global system – the Global Influenza Surveillance and Response System (GISRS), in collaboration with other global experts.
The new variant has not been incorporated, and is not part of the composition of the latest vaccines produced for the Northern Hemisphere influenza season, the WHO expert explained.
Still, “early evidence suggests that current seasonal vaccines continue to offer protection against severe diseases and reduce the risk of hospitalisation,” she said.
WHO estimates that there are around one billion cases of seasonal influenza annually, including up to five million cases of severe respiratory illness.
It added that up to 650,000 deaths each year are due to seasonal influenza-related respiratory disease.
