There was a drop in the MMR vaccine take-up during the COVID pandemic.
Coverage across England is also at its lowest for a decade.
The World Health Organisation sets a target of 95% of children vaccinated to achieve ‘herd immunity’.
In Merton, 89% of five-year-olds had received one dose of the MMR vaccines in 2020 and 2021.
But this drops to 72% for those receiving the vital two doses by the time they are five, which gives 99% protection against Measles.