RFK Jr. is a famous anti-vaxxer. How does this make him qualified for President?

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 minuscule 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 ideologue, 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.

Update, May 28, 2024: Since this story was published on May 27, RFK Jr. has been contacted for comment.  

The 5 Stages of Anti-Vax Angst: A guide

Last week the Biden administration was criticized for making some harsh statements about those who refuse to be vaccinated. “For the unvaccinated, we are looking at a winter of severe illness and death — for themselves, their families and the hospitals they'll soon overwhelm. But there's good news: If you're vaccinated and you have your booster shot, you're protected from severe illness and death,” said Biden.

That statement came in for much criticism on social media, especially by those who took the statement out of context. “You’re not going to convince anyone to get vaccinated with such harsh language,” some scientists complained.

Well, true. But as someone who’s been fighting the anti-vaxxers for years, I recognized the Biden team’s statements as Stage 3 of what I’m calling the Five Stages of Anti-Vax Angst. I understand their frustration, because I’ve been there myself. Let’s go through these stages, shall we?

Stage 1: Disbelief. I first encountered the anti-vax movement, in the early 2000s, when I was leading a research project on sequencing the flu virus (here’s one of our papers), and a reporter asked me, quite seriously, if the flu vaccine could cause autism. Huh? I thought. “Well no,” I reassured him, “where’d you get that idea?” I soon traced the source of his concern back to a now-notorious Lancet paper by Andrew Wakefield, which turned out to be fraudulent and was eventually retracted.

Surely, I thought, the solution is simply to educate people better, and to explain that vaccines are the single greatest medical advance in the history of medicine. With better education, the anti-vax movement will quickly fade.

In Stage 1, vaccine advocates simply can’t believe that significant numbers of people believe stuff about vaccines that simply isn’t true. Alas, though, they do.

Stage 2: Frustration. Unfortunately, merely writing articles explaining the benefits of vaccines is not nearly enough. Officialdom (government agencies like the CDC and NIH) constantly issues statements about the benefits and safety of vaccines, such as this CDC website. Scientists and physicians have written hundreds of articles and countless books explaining how beneficial vaccines are, to no avail. For example, renowned vaccine expert Paul Offit wrote an outstanding book warning of the dangers posed by the anti-vaccine movement, called “Deadly Choices: How the Anti-Vaccine Movement Threatens Us All.” That book appeared all the way back in 2010, and yet look where we are now.

Just a year after Offit’s book, journalist Seth Mnookin published “The Panic Virus,” an excellent exposé of the fraud behind Wakefield’s original paper, and on how the anti-vax movement has been aided (often unwittingly) by popular media personalities.

What these books and others reveal is that the anti-vaccine movement is loud, committed, and (unfortunately) highly influential. For every article or book written by a clear-headed vaccine advocate (and there are many!), there are multiple articles and books promoting wildly inaccurate claims that vaccines cause harm. Trying to refute these claims is like playing whack-a-mole.

Scientific bloggers have learned that no amount of patient explanation can get through to some people, and the anti-vaxxers just won’t quit. Eventually, some of them move on to Stage 3.

Stage 3: Anger. This is where the Biden administration finds itself. After months or years of explaining, pleading, and even begging people to get vaccinated, the crazy, irrational, and often angry opposition of anti-vaxxers (or the “vaccine hesitant,” to use a kinder term) can be just too much.

Some people take a long time to reach this stage. Dr. Anthony Fauci, director of NIH’s infectious disease institute (NIAID), has been the public face of the government effort to get people vaccinated for all of the past year. He’s been subjected to inexcusable vitriol, including death threats towards him and his family, and he continues to try to convince people that vaccines are safe and effective. It’s a tough and thankless job. Dr. Peter Hotez, a vaccine expert at Baylor College of Medicine, has been tirelessly explaining the benefits of vaccines throughout the pandemic, and he too has been subjected to awful, hateful attacks. (Dr. Hotez also wrote a highly personal book a few years ago, explaining why vaccines didn’t cause his daughter’s autism.)

Neither Dr. Fauci nor Dr. Hotez has reached Stage 3, but I wouldn’t blame them if they did. Some public-health experts have, though, and one can see why: after trying for months to get people to do something that reduces their own risk of deadly disease, only to meet defiance, one might say “I’m done. You all can just go ahead and get sick.”

Or, as the FDA’s Twitter account responded in exasperation a few months ago, to the never-ending insistence that ivermectin, can cure Covid-19: “You are not a horse. You are not a cow. Seriously, y'all. Stop it.” (Ivermectin is a de-worming agent for horses. It does not work against any virus, including the one that causes Covid-19.)

The comments on Twitter can be far, far harsher. So when Biden warned that the unvaccinated “are looking at a winter of severe illness and death,” I can’t blame him. After all, he’s right.

Stage 4. Persistence. For those who get past Stage 3 (or skip it entirely), there’s a realization that even though some anti-vaxxers are simply beyond reasoning with (I’m looking at you, Robert F. Kennedy Jr. and Joseph Mercola), that doesn’t mean we can’t fight back. We have to recognize that misinformation is out there, and that some people will continue to spread it no matter what we might say. But there are strategies that work to convince others to get vaccinated, and we have to keep trying. That’s persistence.

For example, a study early this year showed that just a dozen people were responsible for a large majority of the vaccine misinformation across most of social media, including Facebook, Twitter, YouTube, and Instagram. I and others have called for social media companies to de-platform these harmful individuals, which could go a long way towards slowing down anti-vax propaganda. Let’s keep trying.

Another strategy, illustrated by Paul Offit’s 2010 book, is to reveal how anti-vaxxers often profit from their misinformation. Some anti-vaxxers have gotten wealthy selling supplements and “alternative” medicines, promoting them with bogus claims that the supplements can substitute for vaccines. If we raise awareness that these quacks are profiting from the spread of misinformation, that can help raise skepticism about their claims. Getting someone to ask questions themselves–to think critically, in other words–is often the best way to get them to reject the arguments of anti-vaxxers.

And even though I might seem critical of the efforts by government agencies to educate the public, I still think they should do it. Indeed, they should do far more than they are doing: in addition to providing facts about vaccine safety and effectiveness, the CDC and NIH could work harder to directly counter the myths and misinformation that are constantly circulating.

I’ve been blogging about the anti-vax movement since 2008, even before I started writing for Forbes in 2010 (see here and here, for example). I’ve long ago lost count of how many articles I’ve written, trying to point out the harm caused by anti-vaccine misinformation, and I’ll keep trying. So I’d say I’m still in Stage 4.

Stage 5. Surrender. In the face of stubborn opposition, and sometimes virulent and personal attacks, some people eventually just give up. It’s easier, of course, to stop fighting people who just don’t want your help, and I can’t blame anyone who does. When I call this stage “surrender,” I don’t mean to suggest that pro-vaccination and pro-science advocates ever accept the wildly misinformed views of the anti-vaccine movement. Of course not. It’s just that some people decide they can no longer spend time on what seems an endless battle.

I’m not advocating that we should ever give up. We can’t, because infectious diseases don’t care if we stop vaccinating ourselves.

So those are the 5 stages of anti-vax angst, as experienced by countless medical and scientific professionals who are fighting misinformation.

And here we are, in the midst of another huge peak in Covid-19 infections, with a significant portion of the U.S.–and of other countries as well–refusing to get vaccinated. The unvaccinated may indeed be facing a “winter of severe illness and death,” even though no one wants that. I don’t blame anyone for pointing out what is very likely to happen. And if the winter ahead is indeed bad, then I place much of the blame on a small number of very loud voices, such as the Disinformation Dozen, who irresponsibly continue to promote harmful untruths about vaccines.

Vaccines are the single greatest public health advance in the history of medicine. Vaccines have eliminated smallpox from the planet, nearly eliminated polio, and made many other previously-feared childhood illnesses a thing of the past. We can do the same to Covid-19, if everyone will just get vaccinated.

No, the COVID-19 vaccine doesn't change your DNA. But it does make some long term changes. And that's a good thing.

Cartoon by: Maki Naro, from
gene.com/stories/the-antibody

One of the common tropes among anti-vaxxers lately is that the Covid-19 vaccine “changes your DNA.” Oh, the horrors!

Do they even know what they mean by that? Almost certainly not. Anti-vaxxers generally have no idea how biology works; often they are so confused that I’m tempted to say they are not even wrong. Even when they are right about something, it’s for the wrong reasons.

Many articles have already been posted explaining that the vaccine can’t alter your DNA, including a wildly popular piece at Forbes and explainers by the CDC and UNICEF.

So let’s dig into this strange notion that the vaccine changes your DNA. First, let’s look at what the CDC has to say:

“Will a COVID-19 vaccine alter my DNA? No. COVID-19 vaccines do not change or interact with your DNA in any way. Both mRNA and viral vector COVID-19 vaccines deliver instructions (genetic material) to our cells to start building protection against the virus that causes COVID-19. However, the material never enters the nucleus of the cell, which is where our DNA is kept.”

I see what they’re getting at here. They’re partly right, but in an attempt to give a simple “no” answer, the CDC got it wrong. It’s true that Covid-19 vaccines don’t directly alter your DNA, and it’s true that they don’t invade the cell nucleus, where your DNA resides. But that’s not the full story.

(The UNICEF article is more accurate and more nuanced, writing instead that “the information regarding harmful effects of the vaccine against COVID-19 on human DNA is unfounded and untrue.”)

Remember that the whole point of a vaccine is to prevent future infections. That means that something in your body has to change, right? So what is different?

Okay, take a deep breath and we’ll dive in. Whenever your body is invaded by a foreign cell–whether it’s a bacteria, a virus, a fungus, or some other pathogen–your immune system starts selecting from among millions of specialized proteins called antibodies, each one a little different. The way it does this is really rather extraordinary: many little pieces of your DNA are cut and pasted together, in millions of combinations, each making a different antibody. Eventually, one of these antibodies “recognizes” the pathogen (by binding to it).

What’s even more amazing is that the successful antibodies are “remembered” by the immune system, in the form of special cells called B-cells that have slightly different DNA! The DNA in these B-cells encodes just the right antibody to recognize the invader–the Covid-19 virus, that is. Once you recover from the infection, some of those immune cells (B-cells and T-cells–it's complicated) persist in your lymph nodes, constantly looking for any reappearance of the virus.

Or, as Ed Yong more colorfully explained:

“Picture the lymph nodes as bars full of grizzled T-cell mercenaries, each of which has just one type of target they’re prepared to fight. The messenger cell bursts in with a grainy photo, showing it to each mercenary in turn, asking: Is this your guy? When a match is found, the relevant merc arms up and clones itself into an entire battalion, which marches off to the airways.”

(For a deeper dive into how the immune system works, see Ed Yong’s feature article on this topic in The Atlantic from August 2020.)

The DNA in these special "memory B-cells is a little bit different from the DNA in all of your other cells. The vaccine itself doesn't stay around, but it "shows" the immune system a few copies of the spike protein from SARS-CoV-2, the Covid-19 virus, and the immune system remembers. And, I should note, a similar change to your DNA happens if you’re infected by the Covid-19 virus itself.

But B-cells are just a tiny, tiny portion of your body. Every other cell type, from skin to heart to lungs to brain, is completely unaffected by the vaccine. And if we didn’t have any way of “remembering” how to fight off infections, then we’d never become immune to anything, in which case the human race would quickly go extinct.

Finally, let me mention one other bit of misinformation. Early in the pandemic, some very well-known biologists at MIT published a paper claiming that the SARS-CoV-2 virus could, through an elaborate and highly implausible mechanism, integrate into the DNA of cells that were infected. This would indeed be worrisome! Many others quickly pointed out that this result could also be explained by more mundane mechanisms (experimental artifacts, essentially), and in the subsequent year and a half, with hundreds of millions of infections, no one has reported a single case where the virus actually did this. So not only is this event (reverse transcription of viral RNA into a human genome) really, really implausible, it also doesn’t even apply to vaccines, which only contain a small fragment of the viral mRNA.

(As an aside, that study by the MIT biologists was highly irresponsible. They were basically showing off their technical skills, saying “look what we can get the virus to do!” without considering how their work might be twisted, once anti-vaxxers got their hands on it. And the CDC response that I quoted above appears to be a direct response to misinterpretations of the MIT study.)

So back to our original question: does the Covid-19 vaccine change your DNA? Not directly, no. But yes, thanks to your own immune system, the overall mixture of DNA in your body is a tiny bit altered after you get any vaccine. Your DNA is also changed every time you recover from an infection, including the common cold. But the only change is in the DNA of a tiny number of immune cells, which hang around as guardians against future infections. And that’s a good thing.