A Bradford doctor has reassured worried parents that changes to immunisations for babies are in the best interests of their children.

Dr Suzanna Mathew, consultant in communicable disease control for the Bradford district's health protection agency, said the new five-in-one injection for babies was a "positive move".

She said the UK was following in the footsteps of other countries, such as Canada, which introduced the vaccine in 1998 and had already administered up to three and a half million doses with no adverse affects.

Dr Mathew was speaking as changes to the childhood immunisation programme were announced yesterday by the Department of Health.

From October babies in the UK will be given a five-in-one vaccine to protect them against polio, diphtheria, tetanus, whooping cough and Hib, a virus which can lead to meningitis.

The vaccine does not contain the mercury-based preservative thiomersal, unlike the existing version.

The preservative has been linked with autism by US researchers, but Dr Mathew also disputed this, saying the old jab was perfectly safe and the changes had been introduced because a campaign to eradicate polio had been so successful the Department of Health was able to move from a live vaccine for polio, to a dead vaccine, which cannot cause polio.

The jab will be given to babies at two, three and four months, with boosters for pre-school children and teenagers.

It replaces the four-in-one vaccine currently given and the live polio vaccine, given by mouth.

Dr Mathew said she could understand the genuine concerns of parents but immunisation remained the most effective way of protecting children from serious, life- threatening diseases.

"We have a high level of cover in the Bradford district with 95 per cent of all two-year-olds vaccinated," she said.

"We see very few cases of these diseases and we did not have a single case of any of them in 2003."

She added the controversy surrounding the MMR vaccination, which was linked to autism, had had little impact on vaccination rates in Bradford, and she hoped these new changes would not affect immunisation rates either.

Dr Mathew said work was already under way to set up training for health professionals, who would also be given training on how to address parents' concerns.

"The new vaccine is a positive move but we have to be sensitive in dealing with the very real concerns of parents and we will try our best to do that," said Dr Mathew.