What causes the winter flu and how does it differ from other types of flu and colds? | Decomplicated
Health experts are warning that the UK could face its most severe flu outbreak in decades this winter, driven by the H3N2 strain.
Hospital admissions for flu in England are rising earlier than usual, reaching levels typically not seen until December, indicating an "unusually early" start to the season.
The H3N2 strain, currently dominant, has evolved with new mutations, potentially reducing the effectiveness of previous immunity and increasing susceptibility.
The expected severity is also linked to fewer people having been exposed to flu in recent years, leaving more vulnerable, alongside colder weather and indoor mixing.
The flu vaccine is strongly encouraged as the "best defence" against serious illness, particularly for eligible high-risk groups, alongside maintaining good hygiene practices.