A new and concerning variant of influenza is spreading across the United Kingdom, with medical professionals reporting a distinct set of symptoms that differ from typical seasonal flu. The strain, identified as subclade K of the A H3N2 subtype, is contributing to significant pressure on NHS services as hospital admissions rise.
Rising Hospitalisations and Service Strain
The number of people hospitalised with flu reached 2,924 per day up to January 4, 2026, marking a sharp increase at the start of the year. This surge has led four hospital trusts to declare critical incidents due to "significant and sustained pressures" on their services. Three of these trusts are in Surrey and one is in Kent.
Surrey Heartlands Trust specifically cited that high winter demand had been 'exacerbated by increases in flu and norovirus cases'. NHS national medical director, Professor Meghana Pandit, stated: “It’s clear that the worst is far from over for the NHS this winter, with hospitals again experiencing a rise in patients admitted with flu and other respiratory virus cases last week.”
Distinct and Severe Symptoms of the New Strain
Doctors are observing a pattern of symptoms that set this flu apart. Key differences include:
- Higher and more persistent fever: Patients are experiencing fevers that can last between five to seven days, which is longer than usual.
- Resistance to common treatments: In some cases, standard fever-reducing medications like paracetamol or ibuprofen are proving less effective.
- Prominent gastrointestinal issues: There are increased reports of vomiting, diarrhoea, and nausea alongside the respiratory symptoms.
- Severe respiratory and bodily aches: A persistent, phlegmy cough is common, accompanied by significant joint and muscle pain.
Dr Mark Loafman, commenting on the trend, noted the prevalence of prolonged fever, while lung specialist Dr Juanita Mora described the combination of high fever, bad cough, and GI distress.
Official Advice and Urgent Calls for Vaccination
Health authorities are urging the public to take preventative action. Health Secretary Wes Streeting emphasised that vaccination "remains the best protection", particularly for vulnerable groups including older people, young children, and those with underlying health conditions. Professor Pandit reinforced this, stating it is still important for people to seek care when needed and that vaccination opportunities remain available.
The NHS advises that most people can manage flu at home by resting, staying warm, drinking plenty of fluids, and using pain relief carefully. However, you should contact NHS 111 or your GP if:
- You are 65 or over, pregnant, or have a long-term medical condition.
- Your symptoms do not improve after seven days.
- You are worried about your child's symptoms.
Immediate emergency care (999 or A&E) is required for sudden chest pain, severe breathing difficulties, or coughing up blood.
As this new flu strain continues to circulate, public health messaging focuses on vigilance for its unique symptoms and underscores the critical importance of getting the flu jab to curb its spread and protect the most vulnerable.
