What a comedown! Robert F. Kennedy, Jr. (born 1954), son of the late RFK, senator and attorney general, has become an anti-vaxer, and a particularly invidious one.  I haven’t really followed his attacks on vax, but “Orac” (the web name of surgeon David Gorski, who’s given me permission to identify him) has, and Gorski has repeatedly attacked the long-time antivaccination stance of Kennedy.  RFK Jr. is not really an anti-vaxer in the sense of opposing vaccinations per se, but opposes vaccinations that contain thimerosal, a mercury-containing compound once used to preserve vaccines. That preservative, he claims, causes autism.

That’s right, I said thimerosal was “once used.” It hasn’t been used in over a decade, except for certain flu vaccines that are used in remote parts of the world where they can’t be preserved by refrigeration. Nevertheless, Kennedy continues to harp on the dangers of thimerosal, including the claim that it causes autism. This claim has been debunked in several studies, and, as far as I know, there are no other health risks of thimerosal in the quantities used in vaccines. And remember, it’s only used in one type of vaccine, and only in remote parts of the world.

But Kennedy harps on, and has a new, longish piece at Alternet reiterating these debunked claims: “An invitation to open debate on Thimerosal.” This is all by way of pushing his new book, one bearing the unwieldy title of Thimerosal: Let the Science Speak: The Evidence Supporting the Immediate Removal of Mercury—a known neurotoxin—From Vaccines.  It came out August 4, but is already garnering positive reviews on Amazon from the credulous.

To get the lowdown on Kennedy’s claims, I wrote to Gorski, long respected for his skepticism about bizarre medical claims, skepticism he displays on two websites.  I asked him about Kennedy, his book, and his claims, and Gorski replied:

“Heh. Just search Science-Based Medicine and Respectful Insolence for ‘thimerosal’and ‘mercury,’ and you’ll find more posts than you know what to do with. . . I could produce dozens more, and not just by me.”

He sent me some examples of columns he’d written debunking the claims that thimerosal is commonly used, that it’s toxic, and that it causes autism. If you want to read the real science, see Gorski’s columns here, here, here, and here. If you can read only one, read the last one, written on June 17 and dealing with RFK Jr.’s book and its claims.

Rather than excerpt and digest them all, I’ll refer you to a new article in Time Magazine, “RFK Jr. joins the anti-vaccine fringe”, that also debunks Kennedy’s thesis. Some excerpts:

But let’s start with a single fact that ought to be, as the lawyers like to say, dispositive: the thimerosal ain’t there. With the exception of the flu vaccine, it was removed from or reduced to trace levels in all vaccines given to children under 6-years-old 13 years ago. You face a greater mercury risk eating seafood and fish—and even that danger is low enough that the EPA recently recommended that pregnant and nursing women increase their intake of certain kinds of fish because the nutritional benefits outweigh the theoretical dangers.

Kennedy is wrong on basic epidemiology too. Autism diagnoses have indeed risen steadily in the U.S. in recent years, but that has been happening in the same period in which thimerosal levels in vaccines plunged. When your cause goes away and your reputed effect increases, well, you really do need to review your class notes on what cause and effect mean in the first place.

Most fundamentally, Kennedy does not get chemistry. Thimerosal is an ethylmercury product. Mercury in general may be a neurotoxin, but it’s in its methylmercury form that it does its damage—and only in particular concentrations. The quantity of ethylmercury that was once in vaccines was so small that it was actually within acceptable limits for the more toxic, methyl form—but it wasn’t even in that methyl form to begin with.

It’s amusing to see Kennedy, in his piece, waffle on the methy/ethylmercury distinction.  Time continues:

. . .As long ago as 2005, he published an anti-vax article in Rolling Stone claiming to reveal how “government health agencies colluded with Big Pharma to hide the risks of thimerosal from the public.” And Keith Kloor, the author of a new Washington Post Magazine profile of Kennedy, reports that last year, in response to a story he wrote on the Discover magazine website labeling this kind of thinking as the nonsense that it is, Kennedy called him up and said bluntly, “I’m trying to figure out whether you are a shill for Big Pharma.”

. . . The worst—and the least explicable—thing about Kennedy and his new cause is the company he keeps. His book is being put out by Skyhorse Publishing—an outfit that also includes the disgraced Andrew Wakefield in its stable of authors. Wakefield is the U.K. investigator whose fraudulent 1998 paper purporting to link autism to the measles-mumps-rubella vaccine set off the entire anti-vaccine wildfire. In 2010, The Lancet formally withdrew the 1998 paper and Wakefield has since been banned from practicing medicine in the U.K. And as for the company Wakefield himself keeps? The foreword to his book was written by Jenny McCarthy.

After I read this, I wrote back to Gorski asking if it was indeed true that thimerosal was still used in flu vaccines, and his response was brief:

Yes, but they are rarely used in children any more, at least not in developed countries. Thimerosal, however, is very important for vaccine preservation in Third World countries, where the refrigeration chain is nowhere near as reliable as it is here.

He then referred me to three other pieces he’s written on the topic, and on Kennedy; they’re here, here, and here. After reading those, it’s clear that a). there are no dangers to using thimerosal in the quantities once employed, and b. even if there were very small dangers, they would be greatly outweighed by the benefit of vaccinating people against influenza.

I haven’t read all of Gorski’s pieces on this issue, but I’ve read enough to know that RFK Jr. is fear-mongering, and in so doing damaging public health. Although he doesn’t oppose vaccination, he still makes claims that will lead people to oppose vaccination, and for no good reason. The fact that he’s a Kennedy will also add unwarranted weight to his claims.  It’s sad to see someone who could use his name to do good act in exactly the opposite way.