Straight jabs

Straight jabs

Vaccines are causing autism in UK, say some doctors
Published on

a controversial study suggesting that autism is a rare side effect of immunisation against measles, mumps and rubella has led to frantic calls for extended research into the safety of multi-component vaccines. These immunise children against several diseases with a single shot.

A team led by Andrew Wakefield of the Royal Free Hospital in London, uk , reports a study of 12 children with behavioural disorders and an inflammatory bowel condition. All were given the measles-mumps-rubella ( mmr ) triple vaccine and nine have been diagnosed as autistic ( New Scientist , Vol 157, No 2124).

Wakefield believes that in rare instances, mmr vaccine causes bowel inflammation, which, in turn, trigger the extreme social withdrawal of autism. However, other experts say that the study is inconclusive.

Frank DeStefano, a vaccine safety specialist at the us Centers for Disease Control and Prevention in Atlanta, says that it is difficult to determine in retrospect whether the symptoms of autism emerged only after the mmr vaccination, which is usually given between 12 and 18 months of age.

DeStefano also points out that millions have been given the mmr vaccine so far. So if autism is a side effect, it is extremely rare. Given this -- and the fact that measles, mumps and rubella are serious diseases -- health experts urge parents not to spurn the vaccine.

But Wakefiled and several other immunologists argue that the new study highlights the need for more research into risks posed by these multi-component vaccines. Some fear that they may "overload" the immune system of some infants.

"With whole-organism vaccines you elicit a range of immune responses," says Richard Le Page of the University of Cambridge. "In theory, this might result in an immune response that is harmful."

However, multi-component vaccines are popular with health officials, since they require fewer clinic visits. Britain's Public Health Laboratory Service is now testing an acellular whooping cough vaccine to be given in a single shot with the triple vaccine against diphtheria, tetanus and polio, and possibly with the hepatitis b vaccine.

Simon March of the Royal Free Hospital, London, and a member of Wakefiled's team, says that current monitoring regimes are inadequate to judge whether such vaccines are safe enough in the long term. "Extending our follow-up of vaccine-safety is going to be important," he says.

Children given vaccines in trials are followed for just a matter of weeks to check for acute reactions. Once a vaccine is in use, it is left to the doctors to report the suspected adverse effects. "They're not going to tell us if they're related to autism or some other disease that happens three years down the line," he says.

Wakefield wants the mmr vaccine to be replaced by individual vaccines, each given one year apart. But uk 's department of health disagrees. "It'd be irresponsible to leave the children unprotected between vaccinations," says a spokesperson. However, the department has commissioned the Medical Research Council to conduct a review of the mmrvccine's link with autism

Down To Earth
www.downtoearth.org.in