About Rationally Speaking
Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.
Tuesday, June 30, 2009
Vaccines do not cause autism
The SkepDoc helpfully traces the history of this pseudoscientific tale, dividing it into three acts. The original claim came from a British doctor named Andrew Wakefield, who in 1998 published an article in the prestigious medical journal The Lancet, proposing that the MMR (measles, mumps and rubella) vaccine may cause autism because 8 of 10 autistic children he had examined seemed to have developed their autistic symptoms immediately after having been vaccinated, according to their parents. If this sounds like pretty flimsy evidence, it is: the paper was eventually retracted by the journal and by most of Wakefield’s co-authors. It turned out that the doctor did not use any controls at all, ignored negative virological studies that had disproved his thesis even before the publication of the paper, had undisclosed financial conflicts of interest in the matter (he was paid by the lawyers of some of the families whose children he used in his research), and had violated ethical rules of conduct (he bought blood by bribing the children at a birthday party). Moreover, Wakefield’s findings could not be replicated by other studies, so you’d think that would be the end of the story. Nope: the bastard — once charged by the British General Medical Council with professional misconduct — simply moved to the United States, where he is happily making money by working in an autism clinic. As a result of Wakefield’s unconscionable “study”, vaccination rates in the UK dropped, cases of measles went up, and children died. Pseudoscience can kill.
Phase two of the craze, according to Dr. Hall, can be traced back to legislation passed (also in 1998) with the aim of reducing the total amount of mercury that children get through the thimerosal that was used in vaccinations. The intention was good, though it turns out that the dangerous form of mercury is methylmercury, not the ethylmercury found in vaccines. Accordingly, the law was not prompted by any published research or serious assessment conducted by the Environmental Protection Agency. Instead, two mothers (!!) conducted their own “research” and claimed that the symptoms of autism are identical to those induced by mercury poisoning. As Hall points out, this is simply false, period. At any rate, thimerosal was eliminated from vaccines in 1999. You would therefore expect the rate of autism to have gone significantly down as a result, if the hypothesis of a causal link were somehow correct. It didn’t, in fact, it went up. Moreover, a dangerous cottage industry of people selling crackpot remedies against mercury poisoning has emerged, with quacks like Mark and David Geier selling a method that amounts to a very painful process of chemical castration for the hefty sum of $5000-6000 a month. Pseudoscience can hurt, badly.
The third phase of this saga identified by Hall is the one that has seen the above-mentioned McCarthy and Winfrey involved, among others, and it is the even broader (and even less substantiated) claim that all vaccines produced by “Big Pharma” are harmful and are causing an epidemic of autism. McCarthy has an autistic child, and of course she is absolutely convinced that her motherly instincts trump science. She apparently realizes the dire consequences of what she is doing, if somewhat dimly. Here is a quote by McCarthy from the eSkeptic article: “I do believe sadly it’s going to take some diseases coming back to realize that we need to change and develop vaccines that are safe. If the vaccine companies are not listening to us, it’s their fucking fault that the diseases are coming back. They’re making a product that’s shit.” The problem is, of course, that current vaccines are in fact as safe as vaccines are going to be, and the dangers are only in Miss McCarthy’s deranged mind. (Incidentally, there seems to be a reliable claim that McCarthy’s son developed autistic symptoms before he was vaccinated, thereby putting in question either the mother’s “instincts” or her good faith.) Pseudoscience can make you a celebrity, the health of the children be damned.
Dr. Hall very appropriately quotes Jonathan Swift in the context of this discussion: “Falsehood flies, and the truth comes limping after.” That, of course, is true for the lies of pseudoscience as much as for those of politics (which was Swift’s main concern). What is astounding and deeply disturbing to me is that America seems to be enthralled with this manufactured controversy about science: a substantial portion of the public is convinced that vaccines are bad, while scientists agree that they are as safe as they can be; half of the public thinks that global warming is a myth, while the overwhelming majority of competent scientists keep telling us that we are in dire straits that are getting more and more dire; and of course more than half of Americans reject evolution, despite the fact that the theory has been accepted in science since the end of the 19th century.
There is no simple solution to this problem, though these “controversies” are making the American population more ignorant (evolution), sick (vaccines) and environmentally unconscionable (global warming) than ever. Scientists and science educators need to do their part to counter this nonsense, of course. But celebrities like Carey and Winfrey ought to stop promoting bullshit because they are sleeping with a nutcase or out of a misplaced sense of wanting to help others from the dangerous depths of sheer ignorance. And of course the public at large has a duty to society to be informed and attempt to make the best decisions based on the most reliable sources of evidence. The information is out there, people, just use your brains.