The uptake rates for the MMR vaccine in parts of North Kirklees are only just half the national average, which means hundreds of children are unprotected against measles, mumps and rubella.

All of the diseases could kill a small child or result in severe disability – with measles having particularly nasty side effects.

And if a pregnant woman catches rubella (often known as German measles) it could lead to the death of the baby she is carrying.

The vaccine is given in two doses, the first at 13 months and the second at three and a half to five years old, as a pre-school booster.

Staff at Kirklees Primary Care Trust say they know of almost 600 children in the area who have no protection at all and a further 395 who had the first injection but not the second.

Beverley Williamson, from the PCT community immunisation team, said: "We really want to get through to people how important it is for children to be protected. We know that there are close on 1,000 children not fully protected in the North Kirklees area. There is an outbreak of measles in Dewsbury now and there have been cases recently in the surrounding areas."

She and her colleagues know that many parents were scared off the MMR vaccine about six years ago when there was a suggestion that there was a link between MMR and autism or bowel cancer. But in February this year that was proved wrong and the vaccine has been declared very safe.

Over the coming weeks the team will be working on one area at a time, contacting families where there is a child who is overdue the vaccine.

They will offer them an appointment and if this is not kept they will be sent another. If they fail to attend that appointment their GPs, health visitors and school nurses will be notified and asked to become involved.

Further information is available at www.immunisation.nhs.uk.