Flu occurs most often in winter in the UK and peaks between January and March.

Impact on the population varies annually dependant on the circulating strains but is a significant burden on the NHS with c. 800K GP appointments annually (E&W)

During the 16/17 winter season, as a result of flu associated complications, there were:

The World Health Organisation (WHO) have estimated that worldwide approximately one billion people are infected annually with the flu virus, with up to 500 000 people dying as a consequence. Older children having the greatest burden of illness, but the highest burden of severe disease (in terms of hospitalisation and death) occur in people with underlying medical conditions, infants , young children, and elderly people.