Fears about vaccines have been around for as long as vaccines have. Ben Franklin, like our other founding fathers, knew a thing or two about these fears—before the first real vaccine was even invented.
Today, however, preventable diseases like measles and whooping cough are on the rise because of unsubstantiated public doubts about vaccine safety. Misinformation in the public sphere, like the thoroughly refuted claim that vaccines cause autism, generates uncertainty and causes people to make decisions about their health and the health of their children based on fear rather than science.
A new and misnamed book co-authored by Robert F. Kennedy Jr., Thimerosal: Let the Science Speak, is filled with exactly the kinds of misrepresentations of facts and slippery slope distortions of research that sway people—often those who are most earnest about seeking information—away from the science.
A minefield of misinformation
UCS has never been shy about calling out political or corporate interference in developing and implementing science-based public policies. We’ve done so many times right here and here on this blog—and here and here and here. If there were a story to be told—as the book claims—about the Centers for Disease Control and Prevention colluding with the pharmaceutical industry on a vaccine policy conspiracy, we would be telling it.
But we aren’t because there isn’t.
The argument the book tries to make—that thimerosal in vaccines is harming human health, specifically children’s brains—is an old one that scientists researched thoroughly and subsequently dismissed years ago. Thimerosal—a preservative containing ethyl mercury—destroys bacteria and has been used to make vaccines safe from contamination since the 1930s. Thimerosal was removed from childhood vaccines in the U.S. in 2001 out of excessive caution by the FDA in the wake of the EPA’s reevaluation of exposure levels to another type of mercury—methyl mercury. Childhood vaccines administered in other countries still contain thimerosal, as do multi-dose preparations of flu vaccines in the U.S. because studies conclude that exposure to ethyl mercury in the amounts present in vaccines is safe.
Methyl mercury, unlike ethyl mercury, is an industrial pollutant. We are increasingly exposed to it through eating fish and other environmental sources, which is why the EPA reassessed exposure standards in the 1990s. The difference between the two types of mercury resembles the difference between ethyl alcohol (ethanol) and methyl alcohol (methanol). Beer, wine, and liquor contain ethanol; we drink it with dinner. Anti-freeze contains methanol; drinking a few shots would kill you.
A doctor prepares to give a MMR (measles, mumps, and rubella) vaccination in Ethiopia. Childhood vaccines outside the U.S. still contain thimerosal because it has proven safe, effective, and economical. Credit: UK Department for International Development via Flickr.
Although the book acknowledges a difference between ethyl mercury and methyl mercury, the authors extrapolate, against the evidence, that ethyl mercury is just as toxic, if not more toxic, than methyl mercury. Even their sources dispute this claim. Referencing paper after paper after paper on the dangers of mercury, the long list of citations seems impressive, until you follow the links and discover these studies are actually about the effects of methyl mercury, not ethyl mercury.
Studies that conclude ethyl mercury is safe are dismissed as flawed via other studies relying on the Vaccine Adverse Event Reporting System (VAERS) with actual dubious methodology. And via the findings of Mark and David Geier, infamous in scientific circles for advocating chemical castration with Lupron for autistic children. And the assertions of discredited scientists like Boyd Haley, notorious for preying on autistic children and their parents by advocating chelation therapy as a cure for autism.
Findings are also taken out of context. The abstract of this 1975 animal study concludes, “No evidence of toxicity due to thimerosal was seen in any animal. Nevertheless accumulation of mercury from chronic use of thimerosal-preserved medicines is viewed as a potential health hazard for man.” Yet the book only concerns itself with the last part and leaves out or dismisses the significant research published since that continues to show no correlation between thimerosal and neurodevelopmental problems.
And, contrary to what the book would have us believe, children are not being exposed to dangerous levels of ethyl mercury in vaccines. Accessible and transparent information provides details on the mercury content of childhood vaccines. Flu vaccines are the only vaccines containing thimerosal children in the U.S. may still encounter, and even these are available in non-thimerosal formulations.
The danger of spreading misinformation about vaccines
When the first vaccine—for smallpox—was invented over 200 years ago, Thomas Jefferson wrote:
“Every friend of humanity must look with pleasure on this discovery, by which one more evil is withdrawn from the condition of man; and must contemplate the possibility that future improvements and discoveries may still more and more lessen the catalogue of evils.”
Jefferson would have been impressed with the progress science has made against diseases such as smallpox, which was eradicated globally in 1980. To continue to fulfill this vision, though, our democracy demands that we rely on facts and reason, not conspiracy-fueled fictions.
Developing vaccines for some diseases like HIV/AIDS and Ebola continue to elude science. Scientists, policymakers, and the public cannot afford to turn back the clock and re-fight old battles with diseases that are preventable with existing vaccines. When misinformation about vaccines spreads, diseases win. Credit: International AIDS Vaccine Initiative via Flickr.
As RFK Jr. should well know from his work on climate change, generating doubt by misrepresenting the science has negative consequences for the public. Because of his stature and good work on so many other issues, he has a special responsibility to get the science right. But this book falls short.
Simply put, spreading misinformation about vaccines leads to unnecessary sickness and death. Reversing humanity’s progress towards eradicating dangerous infectious diseases—and having to re-fight old battles for community immunity—not only costs lives but distracts attention and resources from diseases we have yet to conquer, like the Ebola virus currently devastating West Africa.