Your quick guide to what’s behind the spike in cases, and information on vaccine uptake and public health

A surge in measles cases has prompted the UK Health Security Agency (UKHSA) to declare a national incident. Agency chief executive Jenny Harries says the UK is on a ‘trajectory for everything getting much worse’ because of low vaccination uptake. Nurses have described the situation as frustrating because the virus is preventable with two doses of the measles, mumps and rubella (MMR) vaccine.