Health officials urge public to check they are immunised against measles
There has been an increase in the number of cases of measles in the south of England this year
Health officials are warning the public to check they are fully immunised against measles after an increase in diagnoses.
Public Health England is calling for people to see a GP if they have not correctly received two doses of the measles mumps and rubella (MMR) vaccine.
The health agency's warning comes after 20 cases of the highly-infectious virus were confirmed across London, Cambridge, Essex and Hertfordshire since the beginning of February.
The infections, many of which have resulted in hospital admissions, are predominantly in those aged 14-40.
Dr Kevin Brown, deputy director of Public Health England's virus reference department, said: "The cases we have seen recently have been confirmed mainly in adolescents and young adults.
"It's important to be aware that it's never too late to have the vaccine. So if you've not received two doses of the vaccine in the past - or you're unsure - speak to your GP.
"There's no harm in receiving an additional dose where there is any uncertainty."
Measles - which can cause cold-like symptoms, high temperatures and red-brown blotchy rashes - has been at a historic low in the UK due to immunisation.