LONDON, UK: Ten doctors who co-authored the study which sparked health fears over the combined MMR (measles, mumps, rubella) jab have said there was insufficient evidence to draw that conclusion.

The study, published in The Lancet in 1998, never proved a link between MMR and autism. However, its findings triggered widespread public concern, and a drop in vaccination rates.

The doctors issued a public retraction on March 3. However, it was not signed by two of the co-authors.

The main thrust of the paper was the discovery of unexpected intestinal problems in children who had autism. The doctors say that "much uncertainty" remains about the nature of these changes, and stress it is important that further research continues.

But they admit that they had not had enough evidence to link the problems to the triple jab - and had under-estimated the storm it would cause.

In a statement, to be published in The Lancet, the doctors say: "We wish to make it clear that, in this paper, no causal link was established between MMR vaccine and autism as the data were insufficient. However, the possibility of such a link was raised and consequent events have had major implications for public health. In view of this, we consider now is the appropriate time that we should together formally retract the interpretation placed upon these findings in the paper."

Last month, The Lancet admitted it would not have published the paper if it had known about what it called a "fatal conflict of interest." The British gastroenterologist, Dr Andrew Wakefield, one of the main authors of the study, was carrying out a second study into whether there were grounds for legal action on behalf of parents of allegedly vaccine-damaged children.

Britain's Chief Medical Officer, Professor Sir Liam Donaldson, also waded into the debate, accusing Dr Wakefield of peddling "poor science,."

Dr Wakefield is one of the two doctors who worked on the study who has not issued a retraction.

MMR uptake has fallen as low as 60 per cent in some areas of the United Kingdom, leaving British children vulnerable to disease.

The Wakefield study, which was conducted on 12 children, was done about eight years after the children had been vaccinated and involved parents remembering whether the autism symptoms occurred around the same time as the vaccination.

The suggestion of a link triggered a collapse in public confidence in the MMR vaccine. The possibility of such a link has since been discredited on scientific grounds by several rigorous subsequent studies, but some parents have clung to the findings and health officials say that vaccination rates have fallen dangerously low since its publication.
Immunisation rates also fell in other European countries after the research was published.

"We wish to make it clear that, in this paper, no causal link was established between (the) vaccine and autism, as the data were insufficient. However, the possibility of such a link was raised," the scientists said in the retraction. "Consequent events have had major implications for public health. In view of this, we consider now is the appropriate time that we should together formally retract the interpretation placed on these findings in the paper."

The scientists, led by Dr. Simon Murch, a paediatric gastroenterologist at the Royal Free Hospital in London, work for institutions ranging from the Institute of Child Health in Liverpool, England, to Cambridge University.

The retraction has not been signed by the main author of the original paper, Dr Wakefield, nor by one other author, Peter Harvey.

The group writing the retraction said it could not contact a third scientist involved with the original work, John Linnell.

Dr Wakefield and Dr Harvey could not be reached immediately for comment. Wakefield has maintained that the suggestion of a link between the vaccine and autism is valid, despite the findings of authoritative groups such as the World Health Organisation and the US Institute of Medicine.

(Sources: BBC News Online; Associated Press, March 3, 2004)