Current winter flu jab works in only 3% of cases

This year's flu vaccine only offers a 'low protection' rate and has been estimated to work in just 3% of cases in lab tests, according to health experts.

Public Health England (PHE) said the low success rate of the vaccine was a problem caused by a "mismatch" between the strain of the virus that was used to make it and the strain that is currently spreading around the UK.

Dr Richard Pebody, PHE's head of flu surveillance, said: "It's not possible to fully predict the strains that will circulate in any given season, and there is always a risk of a drift occurring as we have seen this year. However, it's important to be aware that this does not occur every season."

Typically the past effectiveness of the flu jab has been 50% but findings on the virus' "mid-season" effectiveness, published in scientific journal Eurosurveillance, suggest this year there is evidence of "an overall substantially reduced vaccine effectiveness."

The problem with the vaccine offered this year is believed to be because it was developed using an A(H3N2) influenza strain but there has been a 'genetic drift of the virus' towards a main A(H3N2) strain this winter.

PHE reassured the public that antiviral drugs are available as an effective way for doctors to treat patients who do develop flu and who are at greatest risk of becoming seriously ill from the virus.