Misleading and inaccurate anti-vaccination messages on social media are causing more and more children not being immunised against measles.
Analysis of data by the charity Unicef shows that more than half a million children in the UK were not vaccinated against measles over an eight-year period, leaving them vulnerable to a disease that can cause disability or death.
And Unicef says that nearly 170 million children in the world under the age of 10, including 2.5 million in the US, are not vaccinated against measles.
Simon Stevens, chief executive of NHS England, said: “Getting yourself and your children vaccinated against killer diseases is essential to staying healthy, and vaccine rejection is a serious and growing public health timebomb.
“With measles cases almost quadrupling in England in just one year, it is grossly irresponsible for anybody to spread scare stories about vaccines, and social media firms should have a zero tolerance approach towards this dangerous content.”