On Vaccines and Autism
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If you are not convinced that vaccines are safe, please listen to a conversation between Dr. Ginger Campbell of the Brain Science Podcast and Dr. Paul Offit.
Dr. Offit is a pediatrician who is also Chief of Infectious Diseases and Director of Vaccine Education at the University of Pennsylvania School of Medicine. He is co-developer of the rotavirus vaccine and author of the book Autism’s False Prophets: Bad Science, Risky Medicine, and the Search for a Cure. This book should be read to obtain a complete appreciation of the vaccine-autism controversy. However, I found the podcast also highly compelling, because Dr. Offit is extremely knowledgeable and an excellent speaker.
The furor surrounding childhood vaccines began when Wakefield, a British gastroenterologist, published a Lancet article in 1998 claiming to show a link between the measles-mumps-rubella vaccine (MMR) and development of autism in children. Although the study was flawed, it established a clear question: does MMR cause autism? This question has been addressed in 12 different epidemiological studies involving millions of children who either did or did not receive the vaccine. The answer is quite clear: that vaccine never caused autism. Here are Dr. Offit’s thoughts on this:
…science is enormously self-correcting. Andrew Wakefield stands up in 1998 and says, ‘I believe MMR causes autism.’ Well, he raises a hypothesis. It’s a testable hypothesis. It’s been tested. He was wrong. And that’s what I love about science. It’s just enormously self-correcting, and I just think people don’t see it that way1
The original Wakefield paper has been retracted by 10 of the 13 authors. However, the damage has been done: immunization rates with MMR have dropped in the UK, Europe, and the US. The incidence of measles is increasing and there have been deaths of children from the disease. Deaths that could have been prevented had parents chosen to have their children immunized with MMR. The controversy over MMR has lead the public to distrust all viral and bacterial vaccines, and consequently the incidence of other preventable diseases is rising.
The notion that MMR causes autism was accompanied by safety concerns about thimerosal - a mercury-containing preservative used in some vaccines to prevent microbial contamination. The results of several large epidemiological studies found no connection between autism and thimerosal. Nevertheless, the preservative was removed from most childhood vaccines - probably an error, according to Dr. Offit, which simply made parents more suspicious. Autism rates have not dropped since the use of thimerosal was discontinued.
Many parents still do not believe the conclusion that vaccines do not cause autism. Part of the problem is that the etiology of autism is not understood. To a parent, the temporal association of immunization with onset of autism is difficult to ignore. Dr. Offit recalls a story which addresses this issue:
…it’s hard to make a statistical argument, or an epidemiological argument, to a parent who’s seen something that’s very emotional. There’s a story that I tell, because I think it’s a powerful one. My wife is a privately practicing pediatrician in the suburbs. And she was in the office one day and there was a four-month-old sitting on her mother’s lap. And my wife was drawing a vaccine into a syringe that she was about to give this child. Well, while she was drawing the vaccine into a syringe the child had a seizure, and actually went on to have a permanent seizure disorder—epilepsy. And there had been a family history of epilepsy, so she was certainly at risk for that. If my wife had given that vaccine five minutes earlier, I think there’s no amount of statistical data in the world that would have convinced that mother that anything other than the vaccine caused the seizure, because I think those sort of emotional events are very hard to argue against.
Some have accused Dr. Offit of pandering to the pharmaceutical establishment and enriching himself by publishing Autism’s False Prophets. I don’t think these arguments contain a shred of truth. Dr. Offit is donating all the royalties from the boook to autism research. More compelling are his words from the interview:
I worked on that (rotavirus) vaccine because I thought that it could do a tremendous amount of good for children. It’s the same reason that I stand up for the science of vaccines and the science of vaccine safety. I care about children. That’s my motivation.
1Quotations by Dr. Offit are taken from a transcript of his conversation with Dr. Ginger Campbell.
