Children should have two measles inoculations to be fully protected, but 527,000 UK children were not given the vaccine between 2010 and 2017. The NHS has warned that measles cases had almost quadrupled in 12 months, and urged families to get vaccinated. One person with measles could infect ninety others who are not immune. Measles is infectious before the rash appears, so you cannot simply 'keep away'. Public Health England said that unimmunised people were in danger of catching the disease while outbreaks continued in Europe. In Greater Manchester, more cases were recorded this year than in 2018 and 2017 combined. NHS chief Simon Stevens warned that ‘vaccination deniers’ gained traction on social media, leading to false information spreading. Matt Hancock, the health secretary, called for legislation to force social media companies to remove content promoting incorrect information about vaccines.