Health leaders have issued fresh warnings about an “unprecedented” wave of influenza expected to intensify over the coming weeks, amid concerns that cases across the UK have yet to peak. Some schools have already reported widespread illness among pupils and staff.
The alert follows new data showing that the number of people in hospital with flu in England is more than 50% higher than at the same point last year. According to NHS England North West, an average of 295 patients were admitted with influenza last week—more than double the figure recorded during the equivalent period in 2024.
Dr Linda Charles-Ozuzu, regional director of commissioning for NHS England in the North West, said: “The latest published figures confirm our fears that we may be facing the worst flu season in several years.”
Daniel Elkeles, chief executive of NHS Providers, echoed the concern on 4 December, warning that the health service was “facing a tidal wave of flu”. He noted: “It is deeply worrying to see numbers at a record high for this time of year, with cases still rising.” Children appear to be particularly affected. One school in South Wales was forced to close temporarily after more than 250 pupils and staff became unwell.
Professor Punam Mangtani, an epidemiologist at the London School of Hygiene and Tropical Medicine, said one of the circulating strains, H3N2, differs significantly from that seen in last year’s season. This variation may have resulted in reduced immunity within the population, allowing the virus to spread more easily and causing cases to rise earlier. She added that vaccine uptake among older adults appears to be lower this year, and hospital admissions—particularly among people aged over 80—are already increasing.
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Dr Jamie Lopez Bernal, consultant epidemiologist at the UK Health Security Agency (UKHSA), told Sky News that the influenza strain “has evolved more rapidly than usual”, which may further reduce community immunity and fuel transmission, especially among children and young adults.
“Children are key drivers of flu spread,” Professor Mangtani explained. “They have had fewer exposures to previous flu seasons and frequently mix with one another. As a result, they’re often the first to become infected.”
Hospitals across the UK are already reporting significant pressure. Dr Julie-Ann Maney, a paediatric consultant at the Royal Belfast Hospital for Sick Children, described the situation as the most severe influenza outbreak she has seen since becoming a consultant in 2010. She noted that many children are experiencing very high temperatures and prolonged illness due to the virulent strain. Several schools have taken emergency measures to contain outbreaks.
St Martin’s School in Caerphilly, South Wales, temporarily closed after 242 pupils and 12 staff were absent with flu. Headteacher Lee Jarvis reported widespread symptoms including vomiting, diarrhoea, high temperatures, headaches and fatigue. During the closure, the school undertook a deep clean while lessons moved online.
Congleton High School in Cheshire also shut temporarily in late November for a deep clean after around 200 pupils developed flu-like symptoms.
In Northern Ireland, Ebrington Primary School in Londonderry saw 170 pupils absent in a single day. Principal Brian Guthrie compared the disruption to “being back in Covid times”, with multiple illnesses circulating simultaneously.
Official data shows confirmed flu cases in Northern Ireland rising from 273 to 954 in just two weeks.
In Leeds, Wigton Moor Primary School has suspended singing during assemblies, opened windows and reintroduced hand sanitiser to help reduce transmission. Headteacher Elaine Bown said rehearsals for nativity productions have been challenging but added, “We are doing everything we can not to cancel Christmas.”
Data from the UKHSA up to 24 November shows that children aged five to 14 are testing positive at the highest rate, with 36.25% of PCR tests in this group returning positive results. People aged 15 to 44 had the next highest positivity rate at 20.88%, followed by children aged 0 to four (11.8%). Among older adults, the figures were lower: 9.83% for those aged 45 to 64, 9.31% for those aged 65 to 79 and 7.32% for those aged 80 and above.
Long-term data indicates the same pattern, with younger age groups disproportionately affected. Experts say this is partly due to closer social mixing and lower immunity, while older adults are more likely to be vaccinated—74.9% of people aged 65 and over have received the jab, compared with just 18.4% across the rest of the population. Health officials continue to urge eligible groups to come forward for vaccination in an effort to reduce pressure on the NHS ahead of what is expected to be a particularly challenging winter.
