News

10th August 2005

Immunity not reduced by multiple vaccinations

Fears that receiving multiple vaccinations increases a child's risk of being hospitalised due to infectious diseases are unfounded according to a new study.

Concerns had been raised that exposure to a number of vaccines 'used up' the immune system, so children could not fight off other illnesses.

But a study by Danish researchers monitoring 805,000 children has found no link.

All children born in Denmark between 1990 and 2001 were monitored by the Statens Serum Institut in Copenhagen, which is linked to the Danish Ministry of the Interior and Health and carries out research into vaccines.

They looked at routine immunisations including MMR, diptheria, tetanus, polio and Hib.

They also monitored how many children were hospitalised with infectious diseases in the five years following their vaccinations.

The diseases included acute upper respiratory tract infections, viral or bacterial pneumonia, viral central nervous system infections, bacterial meningitis and diarrhoea.

They found the only adverse association was for Hib and acute upper respiratory tract infection, but said this was within the limits of what would be expected by chance alone, and not time or vaccine dose related.

There was no link between the number of vaccinations received at one time and the risk of infection.

The team, led by Anders Hviid, said they found 15 associations where vaccination appeared to protect against conditions other than those it was targeted at.

They added, "Our results do not support the hypothesis of increased risk of infectious disease hospitalisation after childhood vaccination."

Dr Mary Ramsay, consultant epidemiologist at the Health Protection Agency, said, "Most experts were not concerned that there was any risk of immunological overload from childhood vaccines.

"We know that young infants are exposed to large numbers of antigens in everyday experience and that the immune system has capacity to respond to thousands.

"However, concern amongst the public and a small group of health professionals needed to be addressed to provide more reassurance that vaccination was safe."

She added, "This study suggested vaccination might reduce the risk of other infectious conditions.

"This is consistent with similar studies looking at hospital admission after MMR vaccine."

However, vaccine campaigners have called for more research.

Jackie Fletcher of Jabs, which believes 1,000 children in Britain have been damaged by the MMR jab, said, "I believe there is a susceptible group of children who have vulnerable immune systems, and could be identified before vaccinations were given."

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