The Health Protection Agency has reported a ten-fold rise in measles cases in the first four months of the year.
So far this year, there have been 334 confirmed cases, compared with 33 for the same period in 2010.
The infection is travelling from countries like France, Spain, Germany and Romania who are reporting major outbreaks.
Around two-thirds of cases, 206, have been in south-east England.
Measles normally causes only a rash, cold-like symptoms and a temperature that can last up to two weeks. But in one in 15 cases it can result in complications such as eye infections and pneumonia. It is fatal in one in 1,000 cases.
It is thought parents choosing not to vaccinate their children may be behind the latest outbreak.
Prima Baby's GP Dr Rob Hicks urges parents to give their children the MMR and says it is safe.
Vaccines have to undergo years of clinical trials before they are licensed. Studies from around the world have not found a link, and the majority of experts believe the vaccine doesn't cause autism,' says Dr Hicks.
Most doctors argue against single vaccinations because it means six instead of two injections and research shows the more jabs a child needs, the less likely it is they'll receive the full course,' says Dr Hicks. The longer it takes to be protected, the more chance they have of coming into contact with the infection naturally. This risk increases if fewer children are vaccinated.
Worried about taking your child for their vaccinations? Heres how to best prepare your baby for her first injections, by Dr Miriam Stoppard.