Thirty leading pediatricians and childhood vaccination experts wrote an open letter pleading that misgivings about the measles, mumps and rubella (MMR) vaccine could lead to lives lost. They insist that the MMR vaccine is proven safe by science.

The measles, mumps and rubella vaccine was associated to autism in a Lancet paper in 1998.The paper has since been discredited, but nonetheless, immunization rates have dropped recently in the U.K.

The children must be immunized or there is the threat of mass outbreaks and unnecessary deaths

Adequate protection rate for the whole community is set at 95 percent, a significant amount higher than the 83 percent it was last year.

The Health Protection Agency has reported 449 cases this year, a significant increase as compared to 438 for 2003.

The open letter says, "It is not too late to avert this predictable tragedy. It is time that due weight is given to the overwhelming body of scientific evidence in favor of the vaccine." It further adds: "Misguided concepts of 'balance' have confused and dangerously misled parents. We all, media, politicians and health professionals, have a responsibility to protect the health of our children."

A Department of Health spokesperson responded to the doctors' letter saying to BBC, "It is extremely important that parents protect their children from these preventable diseases. MMR is the safest and most effective vaccine."

"We strongly recommend that any parent who wants to make sure their child is up to date with their vaccinations contact their local surgery."