A doctor who touched off a worldwide panic over an alleged link between the MMR vaccine and autism has been barred from practicing medicine over unethical research practices. Britain's General Medical Council struck Wakefield from the medical register on Monday, a sanction analogous to disbarring a lawyer.
"The investigation focused on how Wakefield and colleagues carried out their research, not on the science behind it," according to the New York Times. That makes it sound like Wakefield's ethical lapses had no bearing on the validity of his research, or lack thereof. In fact, some of Wakefield's unethical behavior undermines the credibility of the study, which made international headlines when it was published in the Lancet in 1998. The report propelled Wakefield to guru status within the international anti-vaccination movement. His research went down in flames, but he's still getting on the Today Show.
Actress turned anti-vaccine crusader Jenny McCarthy alleges that Wakefield is the victim of a smear campaign orchestrated by MMR manufacturers. But the evidence against Wakefield speaks for itself. It's ironic that the anti-vaccination crusaders cast aspersions on vaccine defenders for their (real or imagined) ties to the pharmaceutical industry. It turns out that their hero Dr. Wakefield had several undisclosed conflicts of interest, including a patent on an alternative MMR vaccine called Transfer Factor, which stood to catch on if MMR fell into disrepute.
In 2004, the Lancet partially retracted the paper. A full retraction followed in 2010. Investigative journalist Brian Deer deserves much of the credit for unmasking Wakefield. Over the course of 6 years, the reporter teased apart the undisclosed conflicts of interest behind the celebrated Lancet study. When they found out about Wakefield's shady side deals 10 of his 12 co-authors recanted their contributions to the paper.
Wakefield's original paper purported to study 12 consecutive patients admitted to the Royal Free Hospital with GI symptoms and regressive developmental disorder. Of these, the parents of 8 children recalled that the symptoms came on after the MMR jab.
However, Wakefield did not disclose to the Lancet the he already had a contract worth up to £55,000 with the Legal Aid Board to investigate the link between autism and the MMR in 10 children whose parents wanted to sue the manufacturers of the MMR vaccine. The parents were recruited by a lawyer called Richard Barr who advertised for parents who already believed that their child's autism was caused by the vaccine. So, the fact that 66% of parents in Wakefield's study associated their child's autism with the MMR shot isn't a very impressive statistic.
Four or five of the patients whose cases were analyzed in the Lancet study had previously been studied under the Legal Aid Board contract. In other words, these patients were handpicked twice over. First, they were offered up by parents who had a financial interest in proving the link between MMR and autism. Then Dr. Wakefield cherry picked only 4 or 5 kids from the original pool of 10 to for the Lancet report.
[Update: Wakefield and colleagues may also have falsified their results. They claimed that the children developed symptoms after the MMR shot, but a review of public and confidential records by reporter Brian Deer found that nearly all had begun exhibiting symptoms earlier. Wakefield claimed that the children showed signs of inflammatory bowel disease, but Deer found that pathologists were unable to find evidence of IBD in most cases, according to hospital records. Wakefield also claimed that some children had measles virus in their intestines. Deer tracked down a parent who took samples from her child's gut to three other labs, which were unable to find any trace of measles. Thanks to reader Oonagh in Vancouver for the tip.]
The whole vaccine/autism scare is a classic case of falsely equating correlation with causation. Autism has an intrinsic developmental timetable. One of the most heartrending aspects of the disorder is that apparently normal toddlers can rapidly regress for no apparent reason, leaving parents casting about for answers. Infants and toddlers get a lot of vaccines. That doesn't mean that the vaccines are causing the autism.
Autism diagnosis has risen dramatically since the 1990s. However, most of that increase can be attributed to heightened awareness and a broadening of diagnostic criteria. Social factors also play a role. There is no blood test or scan that definitively establishes the diagnosis. The symptoms of autism can resemble or co-occur with those of other conditions. So, there's a certain amount of subjectivity built into the evaluation process. Which label to apply often depends on what the incentives are for falling in one category versus another.
In the 1970s parent activists organized to resist the diagnosis of autism. As Dr. Steven Novella explains, the medical establishment used to demonize the mothers of autistic children for starving their offspring of affection. In those days, the diagnosis of autism was an unjust indictment which many parents resisted. Autistic children were also eligible for fewer social services than children diagnosed with other kinds of cognitive disabilities (known as "mental retardation" in the day). Now that the refrigerator mother hypothesis has gone the way of the dodo and more resources have become available for children diagnosed with autism, parents and doctors are more comfortable with the diagnosis.
Novella reviews one recent study that found that a child living within 250 meters of another child diagnosed with an autism spectrum disorder is at 42% greater risk of being diagnosed herself. Children who live between 250 and 500 meters of another child who receives the diagnosis are at 22% increased risk. If autism were caused by vaccines (or genes, or too much TV, or pretty much anything hypothesized so far), you wouldn't expect to see that pattern. The study authors decided the most likely explanation was that information about autism was spreading through social networks, thereby increasing the chances that parents would recognize the symptoms in their own children and seek help.
There may be a true increase in autism incidence hidden in all the noise, but fears of a new autism epidemic are overblown.
The bottom line is that there's no evidence that un-vaccinated children are at lower risk of autism. On the other hand, we know for sure that they are at increased risk of all the diseases that they haven't been vaccinated for. For an accessible summary of the epidemiological evidence, check out Frontline's excellent documentary "The Vaccine Wars."
Dr. Wakefield has been kicked out of the medical profession in the UK, but it's already too late. He's already set up shop in Texas.
[Photo credit: flickr user KOMUnews, distributed under Creative Commons. This picture shows an older child getting an H1N1 vaccine, not a toddler getting an MMR shot, but Creative Commons surfers can't be choosers and besides, it's adorable.]