Hospitals across the UK are bracing for a once-in-a-decade flu surge this winter, driven by a mutated strain of the virus that is spreading widely among younger people. The mutated version, a descendant of the strain that caused Australia's worst flu season on record, has become dominant in the UK and triggered an earlier-than-usual start to the flu season.
Scientists first detected the mutated virus in June. Genetic analysis shows it is a subtype of influenza called H3N2, which tends to cause more severe illness, particularly in older people. The mutations may boost transmissibility, with the R value estimated at 1.4 compared to the normal 1.1-1.2. However, it is too early to know if the mutations make infections more severe.
NHS managers are redoubling efforts to vaccinate staff and communities, expand same-day emergency care, and treat more patients in the community to reduce hospital admissions. The UK Health Security Agency (UKHSA) reported that flu cases continue to increase overall, with infections highest in children but creeping up in older people. Health officials expect numbers to rise further as colder weather drives more indoor mixing.
Early data from UKHSA suggests current vaccines are less effective at blocking infections caused by the mutated virus but still provide good protection against severe disease. Vaccine effectiveness against hospital attendance is 70-75% in children and 30-40% in adults. Despite this, less than a third of people with long-term health conditions have come forward for the vaccine.
Dr Antonia Ho, a professor at the MRC-University of Glasgow Centre for Virus Research, urged all eligible individuals to take up the vaccine offer and encouraged others to consider paying for the shot and using lateral flow tests. Caroline Abrahams of Age UK stressed the importance of vaccination for older people, while Elaine Clancy, group chief nursing officer for St George's, Epsom and St Helier university hospitals, said: "We're preparing for a spike of flu on to our wards."
