A medical journal in Britain has retracted a controversial study it published in 1998 that linked the use of a vaccine in children to autism.
The study retracted on Tuesday looked at 12 children suffering from colitis, a gastrointestinal disease.
British surgeon and medical researcher Andrew Wakefield concluded a component of the measles, mumps and rubella, or MMR, vaccine caused the colitis, which in turn led to development problems that are part of autism spectrum disorder.
"It has become clear that several elements of the 1998 paper by Wakefield … are incorrect," The Lancet said in a statement.
Since the controversial paper was published, British parents abandoned the vaccine, leading to a resurgence of measles in the U.K. and elsewhere in Europe.
Subsequent studies have found no proof that the vaccine is connected to autism, though some parents are still wary of the shot. In March 2004, the majority of co-authors on the paper retracted their support for the claims of a possible link between the vaccine and colitis or autism.
A disciplinary panel of Britain's General Medical Council ruled last week that Wakefield had presented his research in an "irresponsible and dishonest" way and shown a "callous disregard" for the suffering of the children he studied.
It also ruled he had brought the medical profession "into disrepute."
Wakefield and the two colleagues who have not renounced the study face being stripped of their right to practise medicine in Britain.
For the study, Wakefield took blood samples from children at his son's birthday party, paying them five pounds each ($8) for their contributions and later joking about the incident.
Meanwhile, fallout from the publication of the study continues.
"It was out there for a very long time. So it's good The Lancet has retracted it. It helps in a small way. But the truth of the matter is the damage has been done," in terms of changes in belief and perception, said Dr. Allison McGeer, an infectious diseases expert at Toronto's Mount Sinai Hospital.
Costs of retraction delay
The retraction is important, but the time it has taken to get to this point dulls its impact, said Dr. Evdokia Anagnostou, a clinician scientist at Bloorview Research Institute in Toronto.
"There is room to study the link between the immune system and autism," she added. "Still, I don't think we have clarified that issue, and I would hope that the money goes towards that route and not again on the MMR hypothesis."
It took a lot of time and effort to debunk the hypothesis, agreed Dr. Bonnie Henry, chair of the Canadian Coalition of Immunization Awareness and Promotion.
"If the amount of money and time and effort had been put into understanding autism, they might have made a lot more gains," in understanding the mechanisms behind the disorder, how to prevent it, and better integrate children with autism into society, Henry said from Ottawa.
The medical publishing industry has made strides to ensure trials are registered properly, people are reviewed appropriately and that conflicts of interest are prominent so people can make up their own minds in controversial areas, Henry added.
Concerns about the MMR vaccine spread to Europe and North America.
In 2007, a large outbreak of mumps was set off in the Maritimes after the virus was imported from the United Kingdom, said Dr. Noni MacDonald, a pediatric infectious diseases expert at Dalhousie University in Halifax.
More than 1,000 cases were recorded over a period of months as that outbreak spread across the country.
Wakefield remains outspoken and said last week that the panel's findings were "unjust and unfounded." His supporters believe he has been the subject of a conspiracy to discredit him.