I’ve written about the anti-vaccine movement and its many proponents more times than I can count. So why write about it again? Because one of them is running for President of the United States.
Robert Kennedy Jr. is famous for two things: first, he’s famous because he’s the son of a former Senator and the nephew of a former president. His father, Robert Kennedy Sr., served as Attorney General under President John Kennedy and then as a US Senator. Tragically, both JFK and RFK were assassinated in the 1960s, and RFK might very well have been elected president in 1968, as he was leading the Democratic field when he was killed.
Having a politician as one’s father does not qualify anyone for office, although many children of politicians use their famous name to win elections. That’s clearly what RFK Jr. is now hoping for.
But what RFK Jr. is really famous for now, and for the past 20 years, is something entirely different. As I wrote nearly a decade ago, Kennedy is obsessed with the notion that vaccines cause autism. He’s particularly obsessed with the thoroughly discredited idea that thimerosal, a preservative used in some vaccines, causes autism.
His efforts to convince people of the harms of vaccines landed Kennedy in the number two position on the infamous list of “The Disinformation Dozen,” This list, created by the Center for Countering Digital Hate, contains “the twelve anti-vaxxers who are responsible for almost two-thirds of anti‑vaccine content circulating on social media platforms.” Yes, this is what RFK Jr. has been focusing his energy on, at least until he decided to run for President.
Ten years ago, Kennedy published an entire book on this topic, called “Thimerosal: Let the Science Speak,” and he promoted it both in the press and in the halls of Congress. He had personal meetings with then-U.S. Senator Barbara Mikulski and Sen. Bernie Sanders to try to convince them to take action based on his claims. Why is it that a scientifically unqualified anti-vaccine advocate got a private audience with two U.S. Senators? Because he’s a Kennedy.
RFK Jr. gives hundreds of speeches a year, and up until the early 2000s, he spoke mostly on environmental issues. I heard one or two of his interviews during that era, and he was quite convincing. His usual argument was that large corporations were engaged in some kind of conspiracy to damage the environment so that they could increase their profits. That made sense to me!
But then he found the thimerosal issue and went completely off the rails. One example was a Salon.com and Rolling Stone article (jointly published in both magazines) that he wrote in 2005, which claimed not only that thimerosal-containing vaccines cause autism, but that “the government” knew about it and had been covering it up. Kennedy wrote that
“The story of how government health agencies colluded with Big Pharma to hide the risks of thimerosal from the public is a chilling case study of institutional arrogance, power and greed.” [quote from RFK Jr.]
Alarming-sounding stuff. The article was full of dramatic claims like this one. The only problem was, all of them were false.
To explain, let’s review what thimerosal is and why it has probably saved many lives. There was never a conspiracy because there was nothing to hide.
Thimerosal is a preservative that was used in many vaccines for decades. Why? Well, as I’ve explained before, early vaccines (back in the pre-WWII era) were administered from multi-dose bottles, in which bacteria would sometimes grow. In one particularly disastrous incident in 1928, 12 children in Australia died from staph infections after receiving the diptheria vaccine from the same multi-dose bottle. After the introduction of thimerosal, bacterial infections caused by vaccination virtually disappeared.
Why the panic from RFK Jr. and others about thimerosal? Well, it’s a mercury-based preservative, and RFK assumed (wrongly) that the tiny amounts of ethylmercury in vaccines caused autism or other neurological problems. One problem with this idea is that ethylmercury is very different from environmental mercury, which is called methylmercury and which can indeed be toxic. Ethylmercury is cleared from the body far more quickly–and the miniscule amounts in vaccines have never been shown to cause any harm.
But many anti-vaxxers, especially RFK Jr., have continued to spread alarming stories about vaccines (particularly through Children’s Health Defense, an organization founded by Kennedy), and a disturbing number of parents have withheld vaccines from their children because they didn’t know who to believe.
In the late 2000’s, in an effort to address the concerns of anti-vaccine alarmists, a special U.S. vaccine court conducted three lengthy hearings in which the anti-vax advocates were asked to present their best cases. One of the cases focused specifically on the question: does thimerosal in vaccines cause autism? In that case, the judge concluded:
“The numerous medical studies concerning the issue of whether thimerosal causes autism, performed by medical scientists worldwide, have come down strongly against the petitioners’ contentions. Considering all of the evidence, I find that the petitioners have failed to demonstrate that thimerosal-containing vaccines can contribute to the causation of autism.”
As a lawyer, Kennedy should have been able to understand this. The science agrees with the court: in study after study, scientists found no link between thimerosal and autism or any other kind of neurological disorder. That should have been the end of the matter, but of course it wasn’t.
Furthermore, as RFK Jr knows, thimerosal was removed from childhood vaccines in the U.S. over 20 years ago, and the rate of autism diagnosis continued to rise after that. This fact alone contradicts his major claim: if thimerosal was fueling an autism epidemic, then cases should have declined after vaccines stopped including it.
What was shocking to me, the first time I heard Kennedy talk about thimerosal in vaccines, was how absolutely certain he was. He came across as a man who remained utterly convinced that vaccines cause autism, despite the mountain of evidence against him.
After RFK Jr.’s Salon article appeared, scientists responded quickly and convincingly, pointing out its numerous flaws and distortions. Salon tried to fix the problem, issuing five corrections before throwing up their hands and removing the article entirely from their website. Rolling Stone also took down the article. Salon’s editor-in-chief wrote an apology, saying
“I regret we didn’t move on this more quickly, as evidence continued to emerge debunking the vaccines and autism link. But continued revelations of the flaws and even fraud tainting the science behind the connection make taking down the story the right thing to do .”
Kennedy has steadfastly refused to admit any errors, ever. When I wrote about him in the past, his website still displayed the original Salon article, without even the small corrections that Salon.com had made. (That website, robertfkennedyjr.com, no longer exists now that he’s running for President.)
Kennedy also published another anti-vaccine book just last year, titled “Vax-Unvax: Let the Science Speak.” (In case you didn’t notice, Kennedy has zero credentials to write a book about vaccine science, but that has never slowed him down.) And in case there’s any doubt about his leanings, early in 2024 Kennedy hired Del Bigtree, a “top anti-vaccine activist,” as his campaign communications director.
By ignoring the scientific evidence that shows that thimerosal and vaccines have no link to autism, Robert Kennedy placed himself firmly in the camp of conspiracy theorists and cranks. He’s also demonstrated breathtaking arrogance. He believes that despite his lack of scientific training, he knows the truth that every scientist who’s studied this issue has missed.
Even worse, Kennedy has used his fame to spread anti-vaccine misinformation, which grew far worse during COVID. Though I doubt he will listen to me (he’s ignored everyone else), Kennedy needs to take a hard look at the harm he’s causing to defenseless children, the elderly, and cancer patients, and anyone else with a weak or compromised immune system.
When I heard Kennedy talk about environmental topics, where I agreed with him, I was impressed by his passion and his seeming command of the issues. But having heard him speak about thimerosal and vaccines, I now realize that he’s a dangerous idealogue, willing to distort the truth so thoroughly that he can’t be trusted on any topic, even ones where I agree with him. His campaign for President, although certainly doomed to fail, is likely to increase the spread of his harmful anti-vaccine tropes.
Finally, I couldn’t help but notice that the bio on RFK Jr’s campaign’s website makes no mention of his anti-vaccine activism, even though it’s been his top priority for the past 20 years, and it’s the main reason he has the visibility he has today. It does mention “his nonprofit, Children’s Health Defense” but doesn’t say that the primary work of that nonprofit is to spread scary misinformation about vaccines. I’m just guessing here, but it appears that some of his campaign advisers have decided that being a famous anti-vaxxer might not be the best qualification for President.
