Vaccines and Autism: Facts and Fears

When I wrote "Should You Refuse Vaccines?," I was not trying to stir things up. I just wanted to say publicly what I say privately to any of my patients who ask that same question. I had the idea that the debate about vaccines and autism was over. And it is over, at least among mainstream pediatricians and related scientists. But, as I learned from your comments to that post, there are still many questions out there. Let me try to answer some of these questions directly:

  • Comment #1: "Why risk it?... Why not wait til they are older and stronger?"

We immunize little babies because many of the diseases we are trying to prevent, like whooping cough, are most severe in the very young. Immunizing later would leave many children without protection when they need it most.

  • Comment #17: "Why not do a study looking at how many children got autism who did not get a vaccine?"

In fact, many studies like this have been done. For example, a study in the British Medical Journal found that rates of autism rose quickly between 1988 and 1999, while the rate of MMR vaccination did not change; thus, there was no connection between the risk of autism and having gotten MMR. A 2008 study in the Archives of General Psychiatry found that the rate of autism in California rose each quarter from 1995 to 2007, even while the amount of mercury in vaccines was cut sharply. A 2007 study in the New England Journal of Medicine tested more than a thousand children ages 7 to 10, and found no connection between mercury exposure in vaccines and neuropsychological problems (although not specifically autism).

  • Comment #24: "Full refusal is one approach. Another is a slower schedule of vaccinations. One at a time instead of three. Why aren't pediatricians providing this as an option...?"

As far as we know, giving vaccines separately does not cut down the side effects. But it would mean babies getting shots much more often (like, every other week). If a parent in my practice really wanted to, I'd spread out the shots as much as possible. But the three vaccines combined in MMR are not sold separately.

  • Comment #45: "When a child receives multiple vaccinations at one time the trace amounts accumulate. If a child gets four, five or more it would seem that they are getting a fair amount of mercury as well."

I don't think so. The amount of mercury in vaccines is so small that even five or ten doses still delivers almost none. But children are exposed to mercury all the time, in polluted soil, water and food. For example, a recent study from the University of Texas found a positive connection between the risk of autism and how close a child lived to a power plant releasing mercury.

I could say more, but many of you have already said it better than me. See, especially, comments 3, 5, 25, and 77. But I do want to put in two more quotes that touch the heart of this tough issue:

  • Comment #42: "I do believe there's a cure for measles ect; but autism? Trust me, the thought of it affecting my off-spring is truly scary."

Actually, there is no cure for measles. In 2006, at least 173,000 people died of measles world-wide, according to the World Health Organization. The thought of autism is scary. And it is especially scary because we do not know enough about the causes, or how to prevent it. But if fear leads you to make choices that increase your child's risk of measles, pertussis, Hib, and other serious infections, without actually lowering the risk of autism, then I think that is a mistake.

  • Comment #22: "Parents who choose not to have the vaccinations administered to their children are not necessarily misinformed. Perhaps they just have access to different information."

Yes, there is a lot of information out there, so much that it is hard know what, or who, to believe. I tend to trust organizations that have a track record of serving children, like the American Academy of Pediatrics, and articles published in respected journals. Click here for the AAP's take on autism. For the studies I cite above and many more, go to PubMed and search for "autism vaccines."