JAPAN: A study in Japan of more than 31,000 children has provided the strongest evidence to date that no link exists between use of the MMR vaccine and increasing autism rates.
The study, conducted in Yokohama, found the number of children with autism continued to rise even when the measles, mumps and rubella-combined vaccine MMR was replaced with separate, single jabs of vaccine for each ailment.
The findings have been welcomed here by the Department of Health and the Health Protection Surveillance Centre (formerly the National Disease Surveillance Centre). The department said it had always been its contention that there was a sound evidence basis for the use of the MMR vaccine.
"In Ireland, this issue was examined by the immunisation advisory committee of the Royal College of Physicians of Ireland and the Irish Medicines Board. The conclusions were that there is no evidence to support the association between MMR vaccines and the development of autism or inflammatory bowel disease and that the vaccine is safer than giving the three component vaccines separately," it said.
Japan stopped using the MMR jab in April 1993 following reports that the anti-mumps part of the vaccine (a part not used in this State) was causing meningitis.
The records of 31,426 children born in one district of Yokohama between 1988 and 1996 were checked by the researchers behind this latest study.
They counted how many children were diagnosed as autistic by the age of seven and found that the number of cases continued to multiply after the withdrawal of MMR. Rates ranged from 48 to 86 cases per 10,000 children before withdrawal, to between 97 and 161 per 10,000 afterwards.
Fears about MMR surfaced in the UK in 1998 after Dr Andrew Wakefield, from the Royal Free Hospital in London, claimed that the vaccine might trigger autism. The findings, published in the Lancet medical journal, were based on a study of just 12 children and later retracted by most of Dr Wakefield's co-authors.
The findings of the Japanese study were discounted yesterday by Jackie Fletcher, of the British anti-MMR campaign group Jabs. She told BBC Radio 4's Today programme the research was flawed. There could have been a hangover effect in the years following the implementation of the MMR ban in Japan, she argued.
"When the vaccine was banned in Japan in '93, some babies would have received the vaccine just prior to the ban, and the baby would probably have been about 13 months old.
"So to just cover up to '96 . . . autism can take two or three years to be diagnosed," Ms Fletcher said. - (Additional reporting PA)