A conference by the British Medical Association this week includes the release of an open letter from 30 pediatricians and vaccine experts, calling on the media and other health professionals to stop casting doubt over the safety of the MMR vaccine.

After a study was published in a medical journal in the late 1990s, which said there was a link between the MMR vaccine and autism, the numbers of parents taking up the vaccine (given at one year and then pre-school, to protect children against mumps, measels and rubella) have dropped dramatically.

Despite repeated government health reports claiming the link was not proven, and many studies internationally which suggest there is no clear risk, parent campaigners have had a marked affect on the number of children being vaccinated.

The take-up of this vaccine needs to be around 95 per cent of the child population to guard against a serious outbreak, but it is currently around 88 per cent and much lower in some areas.

Campaigners say there should be single vaccines for these illnesses, but the BMA and other experts believe that the delay caused by giving a course of seperate injections leaves small children exposed to serious and potentially fatal illnesses like measels, with single jabs offering no clear benefit.

The letter outlines the likelihood of increased incidences of measels outbreaks (which spread through unvaccinated groups but can then affect babies who are too young to have the initial jabs yet). So far this year there have been more cases of measels (which can cause brain damage) than there were in the whole of 2003.

For advice from the NHS, go to www.mmrthefacts.nhs.uk. For the view of parent groups concerned about multiple vaccinations and certain particular injections, go to www.jabs.org.uk.