Donald Trump is the Republican president-elect, and now champion of the far right. Robert F. Kennedy Jr. is a staunch Democrat, a member of perhaps the most prominent family of that party, who just five months ago referred to Trump as “dangerous” and a “demagogue.” Yet they were recently able to meet over common ground. Unfortunately that common ground is belief in absurd conspiracy theories about the safety of vaccines.

There are now two versions of what was discussed in the meeting. RFK Jr. claims that Trump asked him to head a presidential commission on “Vaccine safety and scientific integrity.” However, shortly after this announcement the Trump team clarified that Trump and RFK Jr. met to discuss an “Autism panel” but that no final decisions or offers were made.

In any case, the alliance of Trump and RFK Jr. should put a chill down the spine of anyone who cares about the integrity and effectiveness of the vaccine program, the mission for the Centers for Disease Control (CDC), and healthcare in the US. Both men embrace crank anti-vaccine claims and conspiracy theories. Both also deny that they are “anti-vaccine,” but that claim is just spin, and doesn’t pass the sniff test.

It is unfortunately not uncommon for science deniers to deny that they are deniers, to instead present themselves (and to be referred to in the press) as “skeptics” (a moniker they do not deserve), and to present their positions as reasonable moderate positions between two extremes. Meanwhile, at the core of their beliefs is the denial of established science in the service of an ideological agenda, in this case one that is decidedly anti-vaccine.

Trump is on record many times, over years, including during the recent Republican Primary debates, that he believes the current “monster shot” of vaccines given to children causes autism. As usual, his thoughts are frequently expressed in tweets:

Trump has rejected the consensus of expert opinion and instead embraces cherry-picked anecdotes. Because of this many of us worried that Trump would become the “anti-vaccine president.” It seems those fears were warranted.

RFK Jr.’s anti-vaccine history

RFK Jr. is an environmental lawyer who at some point became convinced that mercury in the thimerosal preservative in some vaccines was causing the alleged autism epidemic. This belief has evolved into an elaborate conspiracy theory. Laura Helmuth, who had a long conversation with RFK Jr. about his beliefs, summarizes them well.

He believes not only that thimerosal is responsible for an epidemic of neurological disorders in children, including autism, but that scientists and the CDC know about the connection and are deliberately covering it up in service to the vaccine industry. Further, the press is so cowed by the awesome power of the CDC that they are too afraid to challenge them or seriously investigate their alleged malfeasance.

This is a classic grand conspiracy, which gets bigger and bigger the closer you look because of all the people who would have to be involved. In this case the conspiracy would have to involve not only the CDC, but pretty much the entire medical establishment, the Federal government, vaccine manufacturers, and the media. In fact it would have to include all of us here at Science-Based Medicine. This would also have to be an international conspiracy, as it seems every country has fallen for it.

What evidence does RFK Jr. have for his grand conspiracy? He points primarily to two things:

  1. Scientific studies in the public domain that seem to point to the neurotoxicity of mercury. In this case he is substituting his own reading of the medical literature for that of all the experts in the world (while acknowledging that he has no science background).
  2. At times, when he is able to get a scientist alone and back them into a corner, they “collapse like a house of cards” and admit to him personally that it’s all a lie and a cover up. Of course, when those same scientists are later contacted by the media they say that RFK Jr. misrepresented everything that they said.

What I suspect happens in these cases is, essentially, an extreme example of confirmation bias, which sits at the core of much conspiracy mongering. RFK Jr. likely asks many leading and loaded questions, pushing scientists until they say something that can be misinterpreted and taken out of context to seem as if it supports his conspiracy theory. He “reads between the lines,” and in his mind he turns over what they said until it becomes a straight-up admission of guilt. RFK Jr. probably really believes that the scientists confessed to him.

That is all he has. He has no concrete evidence, no smoking gun (grand conspiracy theorists never do). He only has his own misreading of the scientific literature and his own misreading of what scientists have personally communicated to him (while denying his interpretation of what they said).

This makes him an anti-vaccine conspiracy theorist and crank. This is the man that Trump allegedly wants to put as chair of a panel to investigate a possible link between vaccines and autism and “scientific integrity.” There are many analogies I could make here, such as putting in charge of NASA a moon landing hoax conspiracy theorist, or many of the other cabinet appointments he actually made.

Once again: There is no link between vaccines and autism

This is well-worn territory, but I do have to remind everyone what the scientific evidence actually says. First, there is no autism epidemic (or “holocaust”, as RFK Jr. famously called it). Autism diagnoses have increased in the last 30 years, but this has been clearly demonstrated to be an artifact of increased surveillance, broadening the definition, and diagnostic substitution. When you apply the same criteria to the diagnosis in different age cohorts, you find, as a recent study did, that the prevalence of autism is completely unchanged in the last 20 years.

Further, there is no link between mercury, thimerosal specifically, or vaccination and the risk of autism. Not only is there no evidence for causation, there is no true correlation to explain.

The anti-vaccine movement largely based their false beliefs in a link on the fact that autism diagnoses (again, not true prevalence or incidence) was increasing in the 1990s as the number of vaccines given in the vaccine schedule was also increasing. We love to point out that, so was the sale of organic produce. By the end of 2002 the CDC had mandated the removal of thimerosal from all vaccines in the routine vaccine schedule. Thimerosal only remained in some multi-dose flu vaccines, but is being phased out there as well.

The bottom line is that the total dose of thimerosal to which children in the US were exposed through vaccinations dramatically decreased from before 2000 to after 2002. If, as the anti-vaccine movement claimed, rising thimerosal dose was responsible for an increase in autism, then the removal of thimerosal would be followed by a dramatic decrease in new autism cases. In fact, they predicted exactly that, and then waited for their vindication.

That vindication never came. It is now 15 years later, and the rate of autism diagnoses continued to increase at the same rate as before thimerosal was removed. (It has to plateau at some point, as autism diagnoses meet the true autism prevalence.) The removal of thimerosal did not cause even the slighted blip in autism incidence or prevalence. This natural experiment has been replicated in other countries as well.

It is impossible to overstate how solid this evidence is. It is rock-solid unequivocal evidence that thimerosal had no role to play in autism. Despite this the anti-vaccine movement desperately flailed around, in their motivated reasoning, for anything that could save them from this cold, hard fact.

This did not stop RFK Jr. from editing in 2014 a book, Thimerosal: Let the Science Speak: The Evidence Supporting the Immediate Removal of Mercury—a Known Neurotoxin—from Vaccines. Such an ironic title, as the science has spoken, and thimerosal was removed from vaccines.

Many in the anti-vaccine movement have also quietly moved on (while never admitting defeat over thimerosal) to other ingredients in vaccines. It’s the formaldehyde (it’s not), or the aluminum (it’s not) – anything, but it has to be something in the vaccines. This is because they are, despite the protests of some, anti-vaccine. It always comes back to vaccines.

Meanwhile, scientists have been making steady progress showing that autism is a genetic disorder that develops in the womb. This doesn’t mean there are no environmental factors playing any role – scientists are wary of making absolute statements – but the disorder is clearly dominantly genetic.

Both Trump and RFK Jr. also advocate for a “slow vaccine” regimen. They present this as a moderate position, but it is just another anti-science position. The vaccine schedule is not arbitrary. It is evidence-based, and designed to protect children as soon as possible to prevent diseases. In fact, this has also been studied. The routine schedule has been directly compared to delayed schedules. What the scientists found is that the delayed schedules do not reduce the incidence of any diseases or disorders, but it does increase the risk of contracting vaccine-preventable diseases. This just confirms the CDC schedule.

What happens now?

We will have to wait and see exactly what comes out of the meeting between Trump and RFK Jr. It seems certain that nothing good will come out of it. RFK Jr. has been asked about the meeting, and said:

He is troubled by questions of the links between certain vaccines and the epidemic of neurodevelopmental disorders including autism. And he has a number – he told me five – friends, he talked about each one of them, who has the same story of a child, a perfectly healthy child who went into a wellness visit around age 2, got a battery of vaccines, spiked a fever and then developed a suite of deficits in the 3 months following the vaccine.

He said that he understood that anecdote was not science, but said that if there’s enough anecdotal evidence… that we’d be arrogant to dismiss it. Those were his words.

I seriously doubt that Trump understands the limits of anecdotal evidence, otherwise he would not be citing it to counter the mountain of careful evidence compiled by actual scientists. Similarly, RFK Jr. does not seem to understand the limits of pre-clinical evidence, and that showing toxicity in a petri dish does not mean that toxicity happens in people at the doses to which they are exposed.

When asked who he might have on an autism or vaccine panel, RFK Jr. was vague. One can only imagine a panel packed with anti-vaccine cranks, and with the power to make recommendations to a sympathetic president over the future of the CDC and healthcare in the US.


Posted by Steven Novella

Founder and currently Executive Editor of Science-Based Medicine Steven Novella, MD is an academic clinical neurologist at the Yale University School of Medicine. He is also the host and producer of the popular weekly science podcast, The Skeptics’ Guide to the Universe, and the author of the NeuroLogicaBlog, a daily blog that covers news and issues in neuroscience, but also general science, scientific skepticism, philosophy of science, critical thinking, and the intersection of science with the media and society. Dr. Novella also has produced two courses with The Great Courses, and published a book on critical thinking - also called The Skeptics Guide to the Universe.