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Monday, March 27, 2023

Prevalence and Antivaxxers

  In The Politics of Autism, I analyze the discredited notion that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread   Examples include measlesCOVID, flu, and polio.

The CDC report on autism prevalence has produced a predictable response from antivaxxers.

David Gorski at Science-Based Medicine:

Going back over my posts on this blog and my not-so-super-secret other blog, I found that antivaxxers were flipping out over vaccines as a cause of autism in 2018 (when the CDC reported autism prevalence was reported to be 1 in 59), in 2014 (when the CDC reported autism prevalence was reported to be 1 in 68), and in 2012 (when the CDC reported autism prevalence was reported to be 1 in 88). So did our founder Steve Novella, who wrote in 20092011, and 2014 about how true autism prevalence has almost certainly been unchanged over the last two or three decades.

Rising autism prevalence dating back to the 1980s has, ever since the myth that vaccines cause autism arose in the 1990s, fueled an antivaccine narrative that there is an autism “epidemic,” which in some cases has even been called a tsunami, an intentional comparison with a devastating natural disaster that sweeps away everything. At the same time, any scientific pushback against the claim that vaccines are the cause of increasing autism prevalence would be attacked as “denial.” It is a narrative that continues, with longtime antivaccine activist Mark Blaxill having pontificated on it in an interview after he’d somehow managed to publish an article with Toby Rogers and, yes, Cynthia Nevison in a bottom-feeding peer-reviewed journal less than two years ago.

Each time the CDC releases new figures for autism prevalence, along with its analysis of those figures (publications that almost always show up near the end of March, just in time for Autism Awareness Month), antivaxxers regurgitate the same argument: “Autism prevalence is still skyrocketing! It must be environmental factors (translation: vaccines, pollution, high fructose corn syrup, heavy metals, but mostly vaccines), but the CDC is ignoring these potential causes. In fairness, no one rules out environmental contributors to autism development that can alter the risk; it would be irresponsible to do so for a condition that is as multifactorial as autism. However, the evidence, as summarized by Steve and me (and many others) is that, by far, the largest contributor to autism is genetic, a conclusion that continues to be reinforced by more recent studies, to the point that signs of autism have been detected in the fetus, with the contribution of environmental factors being estimated to be between 7%-35%, but possibly as low as zero.