PlayIncreasing cases of measles have triggered a fresh call for parents to make sure their children have had the MMR jab.
Take-up of the vaccine dropped following fears it was linked to autism with around three million youngsters missing out.
The Department of Health said measles was on the rise again as a result and is now making extra doses of the vaccine available and pledging more cash to help NHS trusts vaccinate youngsters in their area.
Trusts in London will receive an extra £60,000 while those outside London will get £30,000.
Professor David Salisbury, director of immunisation at the Department of Health, said: "Parents who have not had their children vaccinated with the MMR vaccine should do so now.
"The evidence on MMR is absolutely clear - there is no link between the vaccine and autism."
He added: "The MMR vaccine coverage is not high enough to remove the threat of recurrence of measles outbreaks. Measles is serious and in some cases it can be fatal. Delaying immunisation puts children at risk."
Estimates suggest that a measles epidemic in Britain could result in 30,000 children and young people being affected, or more than 100,000 in a worst case scenario.
Dr Patricia Hamilton, president of the Royal College of Paediatrics and Child Health, said: "We cannot stress too strongly that all children and young people should have the MMR vaccine. Overwhelming scientific evidence shows that it is safe."
A joint report published earlier this year by the Health Protection Agency, Guys Hospital and Manchester University suggested no evidence of a link between the MMR vaccine and autism.
© Independent Television News Limited 2008. All rights reserved.