The number of measles cases has soared, leading to concern of an epidemic as a result of fears that the MMR vaccine could cause autism, health officials said on Friday.
There were 1,049 confirmed cases of measles in England and Wales up the end of October, already surpassing last year's total of 990 and the largest number since new monitoring methods were introduced in 1995, the Health Protection Agency said.
It said the fears about the MMR jab had led to a rise in parents choosing not to have their children vaccinated.
"This rise is due to relatively low MMR vaccine uptake over the past decade and there are now a large number of children who are not fully vaccinated with MMR," said Dr Mary Ramsay, an immunisation expert at the HPA.
"This means that measles is spreading easily among unvaccinated children. There is now a real risk of a large measles epidemic. These children are susceptible to not only measles but to mumps and rubella as well." In 1998, Dr Andrew Wakefield of Royal Free Hospital in London and colleagues sparked a fierce worldwide debate among scientists by suggesting the MMR jab could cause autism.
Before his comments more than 90 percent of children were given the MMR jab but when his now discredited views were made public that fell to 80 percent.
The largest study into the alleged link reported in February that there was no evidence the vaccination caused the development disorder.
Health bosses are now carrying out an MMR "catch up" programme to try and identify those who have missed out on the jab and offer them another chance to have it.
Evidence suggests there is a real risk of a large measles outbreak of between 30,000 to 100,000 cases in England, mainly centred in London, the HPA said.
"Measles is a very serious infection as it can lead to pneumonia and encephalitis, even in healthy children. It is highly infectious: it can be passed on without direct contact before the rash appears," said Ramsay.
"It is never too late to get vaccinated."