The NHS has issued an urgent warning as flu cases rise sharply with children returning to school after the half-term break. The UK Health Security Agency (UKHSA) is expected to release weekly infection data confirming this surge, which experts fear may soon affect older populations as well. The head of the NHS has cautioned that Britain could face its worst flu season on record this winter.

Data from Australia, which is six months ahead in its flu season, indicates that infections have reached the highest levels since records began in 2001. Additionally, schools in Japan have closed due to a flu epidemic. Dr Suzanna McDonald, national lead for the influenza programme at UKHSA, stated, "Flu has hit early this year and will only spread in the coming weeks. Many people often think they have flu when they only have a bad cold. If you get flu, it is nasty and for some more vulnerable it can be deadly."

Duncan Burton, Chief Nursing Officer for England, emphasised the urgency of vaccination, saying, "With just weeks left to ensure best protection against the worst of the flu season, we are issuing an urgent SOS to the eligible people who have yet to get jabbed this year. It is vital that the public use the over 2.4 million available appointments we have running next week to stamp out this early wave of flu cases and help shield themselves ahead of winter, when viruses tend to circulate and the NHS faces increased pressure on its services."

UKHSA estimates indicate that flu-related deaths in England rose to 7,757 last winter, up from 3,555 the previous year. Child deaths involving flu also increased from 34 to 53. Elaine Clancy, chief nursing officer at St George's, Epsom and St Helier hospitals, expressed concern about the upcoming winter, stating, "Last flu season was particularly nasty and we're very concerned that this year could be even worse - we're preparing for a spike of flu onto our wards. We see people dying every year from flu and sadly thousands more will likely this year. I strongly recommend booking your jab now, as it takes up to 14 days to fully kick-in."

Both Australia and Japan have faced severe flu outbreaks due to a new strain, H3N2, which has mutated to evade immunity from previous vaccines. While vaccinations still provide significant protection and can prevent serious illness, their effectiveness has diminished compared to previous years. Sir Jim Mackey, chief executive of NHS England, noted, "Australia has just endured its worst flu season on record - over 410,000 cases - and all the signs suggest the NHS will face similar challenges in the months ahead. From December through to March, our hospitals will be at capacity."

Health officials in Britain have already warned that flu has arrived a month earlier than usual, raising concerns that not enough eligible individuals are taking advantage of the free NHS flu vaccine. As of now, NHS England reports that 13.3 million flu vaccines have been administered this autumn, but a significant number of eligible groups, particularly those over 65, remain unvaccinated. Latest figures show that two out of five care home residents have not received their vaccine. Parents are urged to complete vaccination consent forms for their children in schools or to book appointments for 2 to 3-year-olds to ensure protection against flu ahead of the Christmas holidays.