Autism and Vaccines

Do vaccines cause autism? For many years a debate has raged on about whether there is a link between autism, the Measles-Mumps-Rubella (MMR) vaccine, and thimerosal, the mercury-derived preservative that was long used to keep vaccines from spoiling. Over the weekend, Pediatrics published a study showing no link between the MMR vaccine, thimerosal, and autism.

Perhaps you’ve not heard of this issue. We hadn’t, until around the time Eli was getting the bulk of his vaccines. Autism rates in developed nations have been rising sharply over the past few decades, and no good cause has been found. In 1998 Dr. Wakefield thought he’d found one: the MMR vaccine. He and 12 co-authors published an article in the Lancet suggesting a possible link between autism, the MMR vaccine, and a supposedly new type of bowel disease. While the paper didn’t outright claim a causal link among the three, Dr. Wakefield did. In a press conference, he called for the combined MMR vaccine to be withdrawn. This was highly publicized in the UK, and led to a drop in MMR vaccinations. Since then 10 of the 12 co-authors have published a retraction, and the London Sunday Times has revealed that Dr. Wakefield had been paid in part by lawyers working on lawsuits against vaccine manufacturers.

However, all of that came to light in 2004, far too late to stop the panic Dr. Wakefield had unleashed. In 2005 Salon and Rolling Stone published an expose by Robert F. Kennedy Jr. claiming that the government covered up the link between thimerosal and autism, and that the link was definite. Medical studies did not back up that claim. The most notable one was a population study of children in Japan, where the combined MMR vaccine was used from 1989 through 1993, after which single vaccines were used. From the article:

The MMR vaccination rate in the city of Yokohama declined significantly in the birth cohorts of years 1988 through 1992, and not a single vaccination was administered in 1993 or thereafter. In contrast, cumulative incidence of [autism spectrum disorders] up to age seven increased significantly in the birth cohorts of years 1988 through 1996 and most notably rose dramatically beginning with the birth cohort of 1993.

And now we have this most recent Canadian population study.

CONCLUSIONS. The prevalence of pervasive developmental disorder in Montreal was high, increasing in recent birth cohorts as found in most countries. Factors accounting for the increase include a broadening of diagnostic concepts and criteria, increased awareness and, therefore, better identification of children with pervasive developmental disorders in communities and epidemiologic surveys, and improved access to services. The findings ruled out an association between pervasive developmental disorder and either high levels of ethylmercury exposure comparable with those experienced in the United States in the 1990s or 1- or 2-dose measles-mumps-rubella vaccinations.

This is an important issue. Vaccines reduce the incident of diseases. For an example of this, take a look at how the pattern of mumps outbreaks in the UK supports this claim. Stopping vaccinations is, simply put, a bad thing. I have sympathy for those searching for autism’s cause. It can’t be easy, especially when you can’t even get good data on how many cases of autism there are. But the vaccine-autism link has gone from tenuous to vapor-thin. It’s time to shift ever-limited research efforts elsewhere.

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13 Comments

  1. Lucian Smith
    on July 6, 2006 at 12:19 am | Permalink

    The weird thing about vaccines is that they’re in some ways susceptible to the ‘tragedy of the commons’, where the best-case scenario for me is that I don’t get vaccinated and everyone else does. Then I get the benefit of not getting the disease (since there’s nobody around to spread it to me), plus I don’t have whatever the small risk is that comes with getting vaccinated. Of course, if everyone follows this strategy, then nobody benefits, so it becomes optimal to get vaccinated once again. In order to acheive balance, a certain fraction of the population have to refuse to get vaccinated, just enough so that all other normal people still get a benefit from being vaccinated. In western societies, this is accomplished by not vaccinating the conspiracy theorists.

  2. Joyous
    on July 6, 2006 at 12:19 pm | Permalink

    I have a friend who is convinced her family have the genetic markers for bad reactions to vaccination. She also has an autistic son. Consequently, she is not having her two younger kids vaccinated. I’m not sure what I think of this.

  3. on July 6, 2006 at 1:28 pm | Permalink

    To me, all the good a vaccine gives the general population far outweighs the risk of not taking them. Lately I have had questions about different aspects of modern medicine but this is not one of them.

  4. on July 6, 2006 at 3:23 pm | Permalink

    This is a lot like the “seat belt decision”: there is some non-zero chance that I’ll have a car wreck in which wearing a seat belt actually causes me more injury than not wearing one (or maybe kills me where I would have survived if I hadn’t worn it). I still always wear my seat belt.

    Life is risk. Nothing is totally safe, and the best thing you can do is play the numbers. In some things (like seat belts and vaccinations) given no further information that I’m unique, the numbers seem to me overwhelmingly in favor of using the protection that’s offered.

    Interestingly, Joyce’s friend has past experience that could be interpreted to indicate uniqueness-by-genetics in the case of vaccinations. The hard part is distinguishing true information from plain old bad luck, especially with such a small “sample”.

  5. Joyous
    on July 6, 2006 at 3:31 pm | Permalink

    As I understood the article she sent me to read on the subject (lost now, alas), the vaccine itself wasn’t the problem, but rather something that was done to it to make it keep longer, so it could mass produced and shipped in large batches. I can’t remember the details now, so that’s undocumented recollection.

  6. on July 6, 2006 at 3:35 pm | Permalink

    As I understood the article she sent me to read on the subject (lost now, alas), the vaccine itself wasn’t the problem, but rather something that was done to it to make it keep longer

    That’s undoubtedly thimerosal. Thimerosal’s derived from mercury, and it was used to preserve vaccines for mass production and longer storage. Thimerosal worked really well for that purpose, but there was a lot of question about whether or not it caused autism. Studies like the one I first referenced have shown that there is likely no link between thimerosal and autism. It’s becoming a moot point, though, as thimerosal’s been phased out of kid’s vaccines since 2000.

  7. missy
    on October 20, 2006 at 9:46 am | Permalink

    I think Thimerosal is still used in some flu vaccines for young children. If anyone has a concern about that, they should ask their doctor whether their particular clinic administers flu vaccines that contain it.

  8. on September 8, 2007 at 2:38 pm | Permalink

    Hi Stephen,

    I am the owner of Autism Today. a large web portal dedicated to the latest news about autism.

    Your article about Autism and Vaccines is very fair and well researched.

    I especially was glad to see you inclusion about the most recent Canadian population study.

  9. on September 8, 2007 at 2:42 pm | Permalink

    Thank you for explaining the Japan Study. Autism Today had not published anything about this study, but we are following up on it now.

  10. Olivia
    on January 18, 2008 at 7:52 am | Permalink

    I have an 11 year old son with Asperger’s Syndrome, and I am very familiar with this whole debate. I can’t agree with you more on this, not getting vaccinations for your kids is just stupid. OMG, my son has AS, the horror! . I would much, much rather risk my child having developmental disorders and trouble communicating than getting polio, especially when there is so extremely little evidence or anything to even suggest to a rational person that this theory has any truth to it. Also, my son showed signs of autistic behavior from birth, before he ever had the first vaccination. And I love my son, everything about him, because he is the sweetest, quirkiest, kindest person I know, and he is extremely intelligent, just not the same as everyone else.

    But in addition to this whole sorry thing leading to parents not getting their kids vaccinated, it feeds into the scam artists and quacks that are feeding on the panic most parents feel when they first learn their child has an autistic spectrum disorder, and unfortuinately too many parents never quite recover from enough to get some perspective. The ‘cure’ people feed on that, promising to ‘cure’ these children of being who they are with treatments that are unpleasant at the very best, and lethal at the worst, and none of them will actually cure autism. One five year old boy died from the affects of chelation treatments that were supposed to remove the mercury from his system and ‘cure’ him of autism because of this panic over vaccinations, and I have had this same ‘cure’ pushed at me so many times I’m getting ready to bite the next person’s head off.

    So, yeah, I am all for raising awareness of the quackery and stupidity behind this.

  11. on January 18, 2008 at 1:31 pm | Permalink

    Thanks, Olivia. I appreciate you sharing that with us. The quackery bit isn’t something I’d thought of, but in hindsight it makes sense.

  12. on November 19, 2008 at 12:47 pm | Permalink

    I’m not sure anyone will see this comment, but it’s quite relevant.

    In September of this year, a book authored by Paul Offit called Autism’s False Prophets was published. Reportedly, Offit does a pretty thorough job of trying to debunk the alleged link between thimerosal in vaccines and autism. I’ve ordered a copy of the book myself.

  13. on November 19, 2008 at 2:23 pm | Permalink

    Offit’s been one of the more public faces of the pro-vaccine contingent, which has led to him getting a lot of flak.

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