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Controversial Autism-MMR Vaccine Study Retracted by Journal: Why Did This Happen - and Can We Forget?
Last month, the prominent British journal the Lancet published a formal retraction of the controversial 1998 study by Andrew Wakefield et al(1), which loosely implied a connection between the MMR (measles−mumps−rubella) vaccine and the development of autism in children. The paper’s findings pointed to a three−way relationship between the MMR vaccine, “pervasive developmental disorder” (autism) and gastrointestinal problems in the study’s small sample of 12 children.(1)
Many readers may not be aware that the study involved this triad of variables. Even more important is the fact that many may not be aware that the findings only implied a vague association between the vaccine and developmental disorder, which, for reasons to be discussed shortly, led to a world−wide pandemic, sparked celebrity and media interest, and lead to a flurry of research that sought simply to replicate (let alone explore the mechanisms behind) the Wakefield connection linking the MMR vaccine to autism.
What was it about this small study that sparked such a far−reaching controversy, only to be retracted 12 years later? Was it bad science – and if so, what made it so? Though the journal and 10 of the 13 authors of the article stand behind the retraction, will the research community and the public be able to delete it from memory – or will it, on some level, always influence the future?
Unsubstantiated Findings and No Evidence of Cause
As noted above, the association between MMR and autism was almost, if not completely, unsubstantiated by the study’s findings. In fact, in the original article, the authors wrote that "we did not prove an association between measles, mumps and rubella vaccine and the syndrome described.”(1) So how did we (the research community, media, and the public) make the leap there might actually be a viable connection between these variables? In a recent editorial in the journal BMJ,(2)
Shortly after the article was published, Wakefield appeared in a “controversial press conference to conflate association with causation and in the eyes of the tabloid press his tiny, skewed sample represented children in general.” Illustrating causation in scientific studies can be tricky – and finding connections or “association” between two variables is sometimes misconstrued as cause−and−effect, as Greenhalgh points out. In the same press conference, Wakefield also suggested, significantly, that instead of administering the vaccine in combination form, it might instead be advisable to give measles, mumps, and rubella inoculations separately, one per year.
It appeared to be largely this combination of events that sparked the media interest, which in turn sparked celebrity, public, and more research interest. Some critics point out that adding to the problem may have been the fact that the media gave “equal coverage to opposing views,” which could have encouraged parents to think that the Wakefield study was actually well−grounded. Jenny McCarthy and Jim Carrey jumped on the Wakefield band−wagon and vocalized their own belief in the MMR vaccine−autism link and publicized their support of the original research. Other parents of autistic children, frustrated and desperate to find an explanation – a culprit – for this baffling disease, followed suit, and were perhaps relieved to have an “answer,” however unfounded it might be. (Even in light of the latest developments, McCarthy and Carrey’s organization still supports Wakefield and his research.)
As the fallout continued in the years following the study’s publication (despite the inability of other studies to confirm the connection(4)) in Britain, MMR vaccine rates began to plummet – and incidence of the measles began to rise.(3)(5)
(1) Comment has been made