Journal retracts flawed study linking MMR vaccine and autism

Science News’ biomedical reporter describes latest chapter in controversy created by now debunked research

The Lancet has retracted a 1998 study that kindled a firestorm of opposition to vaccines by suggesting that autism arose in a handful of children because they had received measles-mumps-rubella shots.

On January 28, the U.K. General Medical Council sealed the fate of the controversial study, saying its selection of participants may have been biased and that lead author Andrew Wakefield committed several breaches of ethics in his work.

The Lancet formally retracted the paper February 2. “It has become clear that several elements of the 1998 paper by Wakefield et al. are incorrect,” the journal editors wrote.

They weren’t the first to lose faith in the study. Six years ago, 10 of the 13 coauthors on the report got queasy about the findings and disowned the paper, fearing it could damage public health efforts.

Since then the Sunday Times of London has done much of the heavy lifting in bringing down the dubious research, publishing details of recruitment bias and ethics questions. The General Medical Council investigated and agreed, leading to the Lancet retraction this week.

Formally, the scientific paper no longer exists.

In the original study, the researchers analyzed the health of 12 children who had developed signs of autism and colon inflammation shortly after receiving MMR vaccinations.

Although the study raised alarms about vaccine and autism that continue to reverberate, a closer look shows warning signs embedded in the paper. The authors were exceptionally cautious in their conclusions: “We did not prove an association between measles, mumps, and rubella vaccine and the syndrome [colitis and autism] described,” they stated flatly. “We have identified a chronic enterocolitis in children that may be related to neuropsychiatric dysfunction. In most cases, onset of symptoms was after measles, mumps, and rubella immunization. Further investigations are needed to examine this syndrome and its possible relation to this vaccine.”

That’s tame language, and 12 patients constitute a tiny study. But Wakefield presented the findings forcefully at the time, saying the study raised a “moral issue” that called for “urgent further research,” according to a BBC story. He said that he couldn’t support giving the vaccine to children.

But criticism of the paper arose promptly, and Wakefield resigned from the National Health Service in 2001 and later moved to the United States. Meanwhile, studies in Britain, Japan and Finland have found no connection between MMR shots and autism.

The final straw for this paper was more like a bale of hay. Children who were supposedly “consecutively referred” to the investigators were not. There was evidence of a pick-and-choose recruitment bias, which discredits the conclusions. What’s more, Wakefield breached ethics standards because he said the kids were referred to him for stomach problems even though he knew that some were part of a lawsuit against MMR vaccine manufacturers. Wakefield even got paid for advisory work on that very lawsuit and had a hand in a patent for a competing vaccine being developed, the Sunday Times investigation revealed.

Wakefield continues to deny any wrongdoing, but many scientists consider the damage already done. In the decade since publication of the Lancet paper, measles vaccination rates fell in Britain. During that time, cases of measles in England and Wales rose 25-fold to 1,370 cases in 2008, according to the British Health Protection Agency.

The flawed report has also helped lead to a wave of antivaccine fervor in the United States (“What’s with the vaccine-o-phobia?, On the Scene Blog, SN Online: 10/31/09).

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