Rhoda Ibrahim, from the Somali Advice and Forum of Information, told BBC Politics London: “It’s always the elderly men and women that don’t speak English and it’s also the mums.
“About 80% of the mums don’t speak English and they’re the ones who are responsible for the children’s vaccinations, schools and all these things.”
Millions of parents in England are being contacted by the NHS and urged to make an appointment to have their children vaccinated against measles, as cases rise across the country.
More than 3.4 million children aged under 16 are unprotected, NHS England said.
Dr Tehseen Khan, a vaccinations adviser for NHS London, said: “The target rate of vaccination among children aged under 16 to prevent measles outbreaks is 95%.
“We are worried that it’s going to come to the capital and when it does it will affect hundreds and possibly thousands of children.”