Doctors will be closely watching as children return to school after figures showed that flu is circulating at its highest level for three years, amid concerns the vaccine may be less effective.
Official figures show 74 outbreaks have been reported in England in the past week and local GPs have been asked to feedback for an indication of how bad the flu season will be amongst younger populations.doctors at Southampton General Hospital have warned the virus has mutated to avoid the immunity provided by the flu jab althoug Public Health England said the jab would still offer "some protection" and was the best option available.
Cases remain below the level seen in the last peak season of winter 2010-11, but are already higher than the peak from the past three flu seasons.
Dr Richard Pebody, head of seasonal flu surveillance at Public Health England, said: "This indicates a proportion of circulating flu viruses circulating in the UK are likely to be drifted.
"Further analysis will take place, but it is not clear yet if these drift variants will become the dominant strain nor if such a drift will result in reduced effectiveness of the vaccine.
"Existing vaccine is likely to still provide some protection and getting vaccinated remains the best way to protect yourself from flu."