Don't vaccines cause autism? Wasn't there mercury in the MMR vaccine that caused neurological symptoms? Well, no.
For years, medical researchers have published careful studies failing to support a purported link between childhood vaccinations - particularly the MMR, or measles/mumps/rubella vaccine - and autism. However, many anxious parents and autism advocates have remained wary of vaccines, mostly based on the work of British doctor Andrew Wakefield. Even after the medical journal Lancet retracted Wakefield's original 1998 article on the subject as fatally flawed - even after Wakefield and a co-author were "stuck off the medical register" (i.e. had their licenses revoked), true believers maintained that Wakefield was a martyr to the truth, hounded by greedy vaccine makers intent on filling their pockets.
Yesterday the British Medical Journal published an article by Brian Deer, a journalist who has gone back and carefully examined the medical records and interviewed the parents of the original 12 patients discussed in the Wakefield paper. BMJ's conclusion: the retracted Lancet paper did not reflect merely carelessness or scientific misconduct. It was barefaced fraud for financial gain.
First, the study. Wakefield's team examined 12 children with neurological and gastrointestinal complaints. Most of the parents suspected the MMR vaccine as the cause of their child's symptoms. Wakefield "found" colitis in most of the children, and also "found" that on average, onset of symptoms occurred 6.3 days after the vaccine.
What Wakefield did not disclose in the article was that for two years before and during the research he was being lavishly paid by a tort lawyer hoping to build a case against vaccine manufacturers. Wakefield's take was $668,000 plus expenses. In a confidential grant application to the UK government's Legal Aid board, Wakefield and his lawyer sponsor voiced their conviction that a vaccine-autism link existed. Their grant application stated, "The objective is to seek evidence which will be acceptable in a court of law of the causative connection between either the mumps, measles and rubella vaccine or the measles/rubella vaccine and certain conditions which have been reported with considerable frequency by families of children who are seeking compensation." (The italics are mine.) In other words, give us the money and we'll give you the evidence to make you rich.
Wakefield knew what he had to show, and he proceeded to manipulate his data to show it. Almost nothing about the data presented in the Lancet paper was fairly represented.
- Patients were recruited through an anti-vaccine group called JABS. Parents were predisposed to blame their children's symptoms on the MMR - in fact, the lawyer had sent out a letter to his clients telling them this doctor believed there was a link. Parents were then interviewed and gently prodded to remember symptoms starting shortly after the vaccine. In one case, a parent remembered that a child was "pale" one week after the vaccine. Prompted further by the interviewer, the parent admitted that the child may have had fever or delirium. In the paper, the fever and delirium are reported as fact.
- The paper reported that 9 of 12 patients developed normally and then regressed, a form of autism called "regressive autism." In fact, no more than 6, and perhaps only one, of the 12 children had this form.
- The children's outside medical records show that only 2 of the 12 patients exhibited their first symptoms within days of their MMR vaccination. The paper changed this to 9 of 12 patients, and reported a fabricated "average" time of onset as 6 days. (Maybe they averaged the patients whose symptoms started many months after vaccination with those whose symptoms started many months before!)
- The hospital pathology department found non-specific colitis (inflamed bowel) in 3 of the 12 patients. Wakefield "re-examined" the specimens and raised this number to 11.
- All of the children suffered from severe constipation, a symptom not associated with colitis and not reported in the paper. Wakefield, a gastroenterologist, did not treat them for this symptom.
-Review by the medical board found that ten children were subjected to unnecessary invasive procedures without ethical approval.
All in all, the British Medical Journal article provides a flat but breath-taking indictment of Wakefield, his partner John Walker-Smith, and their eleven careless but willing co-authors. Does this mean parents and celebrities will finally abandon the mercenary Wakefield and his hypothesis? Probably not. Autism is a devastating disease, and one of parents' strongest impulses when faced with such a diagnosis is to identify an external cause or culprit. Although some parents, when faced with lack of evidence, can accept that the cause of a terrible event is unknown, others cannot. They need someone to blame.
We're creatures who look for patterns to explain our world. When I was a medical student, a young Mexican man came into the hospital with leukemia, which first manifested itself as prolonged bleeding after a tooth extraction. Nothing would shake the belief of this man's family that the dental procedure had caused his leukemia.
So what's the lesson here? Unfortunately, it seems to be that the scientific community has to be yet more vigilant against fraud. When results are truly unexpected, it may be worth asking to look at the raw data. Volunteer peer reviewers can't take that on; it's a responsibility that will need to be shouldered by journal editors in selected (or random) cases. Beyond that, all of us have to guard against our human tendency to reason from anecdote instead of evidence, and our capacity to theorize about vast conspiracies when one person's lies are a lot more likely.