Hospitals across the UK are preparing for a potentially severe flu season, with a mutated version of the H3N2 virus spreading more rapidly than usual. NHS managers have warned that this could be a once-in-a-decade surge, driven by a strain that has become dominant after emerging in Australia’s worst flu season on record.
The mutated virus, which evolved through a process called antigenic drift, has triggered an early start to flu season, more than a month ahead of schedule. Health officials estimate the reproduction number (R) for this season to be 1.4, higher than the typical 1.1 to 1.2, meaning each infected person is expected to pass the virus to more people.
Current flu cases are highest among children but are increasing in older people, who are more vulnerable to severe illness from H3N2. NHS trusts are expanding same-day emergency care, treating more patients in the community, and stepping up vaccination efforts for staff and the public. Contingency plans are in place to bring in consultants and other staff for extra shifts as resident doctors in England continue a five-day strike.
Early data from the UK Health Security Agency (UKHSA) suggests that current vaccines may be less effective at preventing infections from the mutated strain but still provide good protection against severe disease. Vaccine effectiveness against hospital attendance is estimated at 70–75% in children and 30–40% in adults. However, less than a third of people with long-term health conditions have been vaccinated.
Health officials urge all eligible individuals to get the flu vaccine, especially older people, and to take precautions such as using lateral flow tests. Age UK’s charity director Caroline Abrahams said: “The new strain of flu is a worry on what was already predicted to be a big flu season. It is more important than ever that everyone that is eligible gets the flu vaccine and also takes precautions to stay well this winter.”
