More than one-in-five children do not have the full MMR jabs in Tower Hamlets, with the NHS warning that vaccine “deniers” are gaining traction on social media.

Take-up of the vaccine has significantly fallen, while NHS chief executive Simon Stevens blames anti-vaxxers increasing prominence as “part of the fake news movement”.

Latest figures show fewer than eight-out-of-10 children turning five recorded in Tower Hamlets had received the recommended two measles, mumps and rubella jabs, or MMR, between April and September last year. This means 466 children are not fully vaccinated—lower than the national average and far below the 95pc target set by the World Health Organisation.

“The vaccination ‘deniers’ are getting some traction as part of the fake news movement,” Mr Stevens told a Nuffield Trust health summit. “We have seen a five-year steady decline in the vaccination uptake.”

MMR take-up has dropped in the East End since 2014 when 91pc of five-year-olds had the full course of jabs.

The proportion of five-year-olds across the country fully immunised against MMR has dropped from 88.5pc in 2014 to 86.3pc last year.

There were more than three times as many measles cases in 2018 as the previous year.

Mr Stevens revealed that a parent at his own daughter’s primary school had used WhatsApp to express fears about children’s immune systems being “loaded up” with vaccines.

“Nine in 10 parents support vaccination,” he pointed out. “But we are not being helped by the fact that half of them have seen fake messages about vaccination on social media.

“Frankly, it’s as irresponsible to tell parents that their children shouldn’t be vaccinated as it is to say ‘don’t bother to look both ways’ when they cross the road.”

The vaccination is made up of two jabs, the first when babies are a year old, then at three or four before they start school.

The Royal College of Nursing’s Helen Donovan said: “Challenging misinformation is vital to reverse the decline in vaccination uptake and ensure people recognise the protection it offers.”

The rise in measles was “exacerbated by myths propagated largely online”.

Up to one-in-10 children are not fully immune after the first jab, whereas fewer than one-in-100 are fully immunised after the second dose, according to the NHS.