As it goes in medicine, if there is one ground breaking study, follow-up studies soon follow to see if the results can be replicated. And the studies came in. Dozens of them. Two studies, one by Dr. Wakefield and both with significant flaws, showed a relationship between bowel disorders and the MMR vaccine. But none were able to show a link between autism and vaccinations. None.
One of the first studies came out of England. It investigated the relationship between the MMR vaccine and autism. They looked at 498 children and found no difference in the rates of autism between the vaccinated and unvaccinated children.
A study in California looked at the relationship between the increasing number of autism cases and receipt of the MMR vaccine. Between 1980 and 1994 there was a dramatic rise in autism, but the percentage of children receiving the MMR vaccine remained the same. A similar study was conducted in England with the same results.
One of the best studies was done in Denmark between 1991 and 1998. They looked at 537,303 children (compared to Wakefield's 12). They looked at the risk of autism in the vaccinated children (about 80% of them) compared to the unvaccinated children. No difference. There was also no association found between the age at the time of vaccination and the development of autism.
Last month the Lancet officially retracted the original Wakefield paper. (Most of the authors of the paper (besides Wakefield) had already taken their names off the paper.) They effectively said, "This paper should have never been published." But it was published, and oh, the damage it has done.
An average of 1 in 110 children are autistic. The most striking signs of autism appear around 12 to 15 months, the same time the MMR vaccine is given. Statistically, if you have 40 million children, approximately 400,000 of those children will have autism. Out of those 400,000 some of those children are going to start developing symptoms around the time they get their vaccines. They just are. Not because of the vaccines, but just because of coincidence. But try and tell the mother of the one who stopped talking the day after she received her MMR that the two are not related. It's a hard sell.
My own opinion is that there is a genetic component as well as an environmental risk factor. The issue is finding out just what that risk factor is. The only thing that I can conclusively say is that vaccines do NOT cause autism. I know this because they have been studied again, and again, and again. But what about other risk factors. Is it microwaves? Hormones in cows milk? Cell phones during pregnancy? I don't know. And unfortunately, the controversy surrounding vaccines diverts attention and resources from finding out what is really causing autism.
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So there you have it. My autism talk. Now, one small caveat. Although they do not cause autism, I don't think vaccines are 100% safe for every single child. There are some children with underlying disorders who will react poorly to vaccines. My cousin's son, a patient of mine, has a seizure disorder. He had a major seizure after receiving his 6 month vaccines. We are holding off on the rest of immunizations until we can get his seizures under control. But for the vast majority of children, the risk associated with vaccines is much lower than the risk associated with the diseases they prevent. And as more and more children are unvaccinated, the risk of vaccine-preventable diseases increases because the "herd immunity" is less protective.
When it comes down to it, my family is the most important and best thing in my life. I try to not recommend anything to patients or friends that I wouldn't feel comfortable giving Ella. I have given her all of the available vaccines, and felt good about the decision. And it hasn't done her any harm. She's a genius. Just ask her grandma.
Other resources:
I think this is a great article. Her book, Baby 411, is one of my favorites.
Another good one here.