Temple Grandin is wrong on vaccines and autism

Temple Grandin is undoubtedly one of the most famous women with autism of our time. Trained in animal science, Dr. Grandin is a widely read author and noted speaker on autism. April is National Autism Awareness Month, and Dr. Grandin has a new book out, “The Autistic Brain.” Together, this must have seemed like a good time for the New York Times to interview her. Unfortunately, the interview is superficial and not very illuminating, and what Dr. Grandin does say is disappointing. Her take on vaccines and autism, which apparently is elaborated upon in her new book:

Q: In your new book, “The Autistic Brain,” you seriously entertain possible links between vaccines and autism in children, links that scientists have vehemently dismissed.

A: Well, there’s only one vaccine that could possibly be a problem, and that’s the measles-mumps-rubella vaccine. Now that they’ve changed the vaccine, it has fewer antigens, and that would make it a lot safer. But with the old version of the vaccine, I have not yet come across a study that looked at regressives — when a child had some speech but lost it.

Q: There has been a highly emotional battle between mothers of autistic children and the scientists who dispute their theories.

A: I have talked to maybe five or six of those mothers, and that’s the reason I don’t pooh-pooh it. Those mothers have all described the same things. They all have the vaccine, and then they talk about fevers and the weird wailing that started in just a few days. When I brought this up to an expert and asked, “Have you ever studied the regressive group separately?” I got silence.

This is the problem when scientists speak about areas where they’re not experts. I got a lot of flak for my post to my dad addressing vaccines, with people accusing me of being condescending and underestimating his intelligence, but this shows it’s not an intelligence thing at all. (Plus, my dad is plenty intelligent–otherwise why would I bother to write that for him at all?) Grandin is obviously intelligent. She’s also highly educated. She has a PhD in another field. But she’s not an expert in vaccines, as her comments show, and that’s the problem with scientists who speak outside of their area of expertise. Even the very educated amongst us can’t know everything, and it becomes problematic when we use our reputation as scientists to promote something that we don’t have the background knowledge to really understand.

So, Grandin. First, she’s simply wrong about MMR formulation. Perhaps she’s thinking of the DTP vaccine, which now includes an aceulluar pertussis component (“DTaP” or “TDaP”) and therefore has reduced the amount of antigens in the vaccine (not that “excess” antigens are a problem for our immune system, which deals with literally millions of antigens on a daily basis, but that’s another story).

She’s also wrong about studies on regressives. As a scientist, why doesn’t she do her own literature search, rather than “asking experts” and supposedly getting silence? Because she could find several such studies, like this study in the journal Pediatrics or this one in PLoS ONE, if she simply searched.

Her biggest problem, though, isn’t just failure to represent the scientific literature or to understand the MMR vaccine. It’s her over-reliance on anecdote. Simply by the numbers, this correlation between regression and MMR vaccination (or any vaccination) is completely expected. There are currently about 75 million children in the United States. It’s estimated that anywhere from about 1 in 90 to 1 in 50 kids have some kind of autism spectrum diagnosis. Using the higher numbers for the sake of argument and easier math, that’s about 1.5 million kids, and most are diagnosed between the ages of 1 and 5. The first dose of the MMR vaccine is at ~12-15 months of age–when many parents of children with autism are starting to realize that their kids perhaps aren’t communicating like their peers or showing other characteristics of autism, and may think about getting them evaluated. That’s a window of about 1500 days, in which the majority of those 1.5 million kids receive their diagnosis–so averaging a thousand kids a day. Some of those kids will have just gotten shots, and some will have the reactions Grandin mentions–fevers, crying–by chance alone. Some will also wear mismatched socks that day. Some will eat Cheerios for breakfast. But because these aren’t in the news, moms don’t remember the socks, Cheerios, or a thousand other things that their kid did that day that are just as relevant to developing autism as the vaccines they received.

Correlation does not equal causation, and in this case, many, many studies have *disproven* such a link. Talking to “five or six mothers” does not trump years of scientific data looking at many thousands of kids diagnosed with autism, and it’s unfortunate both that Grandin has promoted this type of thinking, and that the New York Times interviewer considered that newsworthy enough to ask Grandin, out of everything else in her book.

Vaccines and autism–can we stick a fork in it now, please?

Last fall, I wrote about a new research paper which tried to replicate some of Andrew Wakefield’s original results, which not only claimed a correlation between MMR vaccination and autism, but also the presence of measles virus in intestinal tissue. Wakefield had suggested that an inappropriate response to the presence of measles virus in this tissue may trigger conditions such as bowel disease and autism. The more recent study was unable to replicate any of Wakefield’s findings–not surprising, since so many papers in the last decade have found no connection between vaccination and autism.

There are plenty of reasons why the study may not have been replicated. The design of the new study was a bit different from Wakefield’s (case-control versus a case series); it had larger numbers; investigators were blinded to the status of the patients and so less likely to bring in bias. However, a recent investigation by the Sunday Times (London) has another reason why the results of the two papers differ: Wakefield made up his data. More after the jump…
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