20/11/2025
🦠 Early flu season alert: what you need to know
This year's flu season has arrived earlier than usual, with UK Health Security Agency (UKHSA) reporting increased influenza activity across the UK.
The current situation, according to NHS publications:
• A drifted strain of Influenza A(H3N2) is predominating this season
• Flu activity is already circulating in the community earlier than typical
• A&E attendances and hospital admissions are rising, particularly amongst older adults
What is a "drifted strain"?
Flu viruses naturally mutate over time, making small changes to their surface proteins. When these changes accumulate, the virus "drifts" and may look different enough that our immune systems don't recognise it as well. This is why flu vaccines are updated each year.
How this affects you
A(H3N2) predominance is associated with higher rates of severe illness and complications, particularly in elderly populations, compared to other flu strains.
Even with drifted strains, the flu jab provides important protection against severe disease. All eligible groups, including those with underlying health conditions and healthcare workers, should get their 2025/26 seasonal flu vaccine as soon as possible.
Understanding flu vaccines
Each year, the flu vaccine is updated to best match the strains of influenza expected to circulate. Because flu viruses mutate frequently, the effectiveness of the flu vaccine can vary each year. Vaccines are designed to provide protection against multiple flu strains circulating this winter, and even when strains drift, vaccination significantly reduces the risk of severe outcomes.
💉 If you're in an eligible group, which includes 65+, pregnant, young children, or those who have underlying health conditions, consider booking your flu jab today. If you're eligible for an NHS flu vaccine, you can:
• contact your GP surgery to book an appointment
• book a free NHS flu vaccination appointment at a pharmacy online
• find a pharmacy that offers free NHS flu vaccination where you can walk-in and get vaccinated without an appointment (if you're aged 18 or over)
Our upcoming Tuesday blog post will share tips on how to boost your immune system.