UK a ‘long way from end of flu season’, expert warns as he reveals why older people are more susceptible to this year’s outbreak

Britain is “a long way from the end of the flu season”, a leading epidemiologist has warned as he identified one of the key factors behind the “stubbornly stable” levels of the virus among older people in the UK, despite an overall decline in cases.

Following an unusually early start to the flu season, levels of flu and respiratory syncytial virus (RSV) have declined since mid-December in most age groups – apart from among those over the age of 85, where cases are “showing no signs of a drop”.

Over-85s are most vulnerable to severe illness and hospitalisation, and data published this week shows the number of patients in hospital beds with flu has risen in the first week of January despite the overall fall in positive cases.

Dr Conall Watson, a consultant epidemiologist at UK Health Security Agency (UKHSA), explained why this age group is particularly vulnerable to this year’s flu strain.

“The virus going around this year is H3N2 and it’s always worse for older adults,” he told the Independent.

“The thing with H3 is that it wasn’t circulating when our current older adults were young people - they didn’t get primed against it as children, so they’re less naturally able to respond to it.

“Subclade K viruses is this new strain of flu and there’s less population immunity to it. That’s where it’s been taking off faster in the population, but, severity wise, it hasn’t shown anything different from other years and the vaccines have been working very well against it so far.”

Dr Watson warned, however, that the cold weather combined with the return to school and work after the Christmas break would likely see flu cases rise again.

The UKHSA extended the cold health alert on Thursday, with all regions remaining under an amber alert until 12pm on Monday 12 January - another concern for older adults who can be more vulnerable to harsh weather.

“We’ve all just gone back to work, kids have gone back to school, and that’s when flu can start to transmit again. We are a long way from the end of the flu season.”

He encouraged anyone eligible for a flu vaccine to take up the offer, adding that early effectiveness data from UKHSA shows that the jab is working effectively against the most dominant strain this year.

Dr Watson said: “I’m very glad people have gone and got vaccinated this autumn. We’re approaching 75 per cent of older adults getting vaccinated and it would be great, obviously, if there were more.”

People over the age of 65 are among the eligible group for the flu vaccine, which also includes those who are pregnant, children from the age of two years and those with certain long-term health conditions.

NHS data published on Friday shows that 2025 was the busiest on record for A&E and ambulance services last year, with a total of around 2.3 million A&E attendances and almost 1 million calls to 999 across England in December alone.

Professor Meghana Pandit, NHS national medical director, said: “The cold weather means we are seeing more vulnerable patients with respiratory problems in A&E and more injuries from slips and falls due to icy conditions, so it remains an extremely busy time.”