Hospitals across the UK are preparing for a potentially severe flu season, driven by a mutated strain of the virus that has become dominant earlier than usual. The new variant, a subtype of H3N2, may be more transmissible and has already triggered a spike in cases, particularly among younger people. Health officials fear a wave of hospital admissions as the virus spreads to older, more vulnerable populations.
The mutated virus emerged through antigenic drift and is a descendant of the strain that caused Australia's worst flu season on record earlier this year. In the UK, it has become the dominant strain, with the flu season starting over a month earlier than typical. The R value for flu this season is estimated at 1.4, higher than the normal 1.1-1.2, indicating increased transmissibility.
NHS managers are ramping up efforts to vaccinate staff and communities, expand same-day emergency care, and treat more patients in the community to reduce hospital admissions. This comes as resident doctors in England continue a five-day strike over pay, prompting hospitals to implement contingency plans, including bringing in consultants for extra shifts and rescheduling appointments.
Early data from the UK Health Security Agency (UKHSA) suggests current vaccines are less effective at preventing infection from the mutated virus but still offer good protection against severe disease. Vaccine effectiveness against hospital attendance is 70-75% in children and 30-40% in adults. Despite this, uptake remains low, with less than a third of people with long-term health conditions having received the vaccine.
Health officials urge all eligible individuals, especially older people, to get vaccinated and take precautions. While H3N2 can cause severe seasons, it is not inevitable; the 2003-24 season with a drifted H3N2 strain led to 12,000 flu deaths in England and Wales, at the lower end of the typical range. Experts recommend vaccination and lateral flow testing to help manage the outbreak.
