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News Roundup [abridged Versions Appear In The Paper Journal]

Japanese study is more evidence that MMR does not cause autism

BMJ 2005; 330 doi: (Published 10 March 2005) Cite this as: BMJ 2005;330:558
  1. Andrew Cole
  1. London

A Japanese research study has provided the strongest proof yet that the measles, mumps, and rubella (MMR) vaccination does not cause autism, by showing that rates of autism in Japan continued to rise even after the triple vaccine was withdrawn.

However, concern remains that the low uptake of the MMR vaccination in the United Kingdom could precipitate a measles epidemic. The Health Protection Agency warns that 90 000 primary schoolchildren could be at risk in London.

The controversy over the vaccine was triggered by a 1998 research paper by gastroenterologist Andrew Wakefield suggesting that the MMR vaccine may be responsible for a particular form of autism (Lancet 1998;351:637-41). A series of studies since then have rejected this conclusion, yet uptake in the United Kingdom of the triple vaccine continues to decline, falling from a peak of 92% in 1995-6 to just under 80% last year.

The latest study, of 31 426 children in the Japanese city of Yokahama, examined the incidence of autism between 1988 and 1996, a period when uptake of the MMR vaccination steadily declined before being withdrawn in 1993 and replaced by single vaccines (published online in the Journal of Child Psychology and Psychiatry).

Yet the incidence of autism continued to rise, from 48 cases per 10 000 children born in 1988 to 117.2 per 10 000 born in 1996. The same pattern was observed for the particular form of autism that Dr Wakefield linked to the MMR vaccine.

“The significance of these findings is that MMR is most unlikely to be the main cause of autism spectrum disorders (ASD) and that its withdrawal can't be expected to lead to a reduction in ASD,” concluded the authors, from the Yokahama Rehabilitation Centre and the UK Institute of Psychiatry.

Meanwhile the Health Protection Agency is warning of the danger of a measles outbreak in London, where MMR uptake is only 70% and in some areas as little as 58%.

“We do fear that if measles was introduced now it could lead to an epidemic with a high number of hospital admissions,” said a spokeswoman. The “capital catch-up” campaign was launched recently to improve uptake.

Liberal Democrat MP Evan Harris, who sits on the House of Commons science and technology select committee, does not think that the new findings will dispel anxiety about the MMR vaccine. “The problem is you can't prove a negative. The people making a link are not using rational arguments, so the usual scientific approach will never convince them, and they will continue to lobby in the media.

“Scare stories start quickly and uptake can fall quickly as a result, but persuading people to return takes much longer.”

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