My Conversation with Robert F. Kennedy Jr.

Twenty years ago, I had a one-hour conversation with RFK Jr. In his current campaign for president, he has referred to that conversation during public appearances. It’s time to set the record straight

Twenty years ago, Robert F. Kennedy Jr. left a message on my voice mail. He said that he had a few questions he thought I could answer. I was thrilled. The son of Robert F. Kennedy, a United States senator and civil rights icon, wanted to talk to me. I was a huge fan of RFK. I had read his book, Thirteen Days, which contained the quote, “The lowest reaches in hell are reserved for those who, in times of moral uncertainty, are ambivalent.” RFK was talking about the Cuban missile crisis, but he could just as easily have been talking about civil rights. It was a call to arms. I couldn’t wait to speak with his son.

When I finally got in touch with him, RFK Jr. explained that several mothers had come to him, concerned about vaccine safety. Would I help him understand the science behind their fears? We spent about an hour talking mostly about thimerosol, an ethylmercury-containing preservative that had been removed from childhood vaccines in 2001. I thought the call went well. I remember telling my wife that night about how I felt confident that I had answered his questions.

Soon after our conversation, on July 14, 2005, RFK Jr. published an article in Rolling Stone that also appeared on the website, Salon.com. It was titled “Deadly Immunity.” Kennedy had sandbagged me. According to the article, I was part of a group of government agents and industry insiders that had "colluded with Big Pharma to hide the risks of thimerosal from the public."

The article was full of misstatements. RFK Jr. claimed that the amount of ethylmercury in vaccines was 187 times greater than the recommended limit, when it was only 1.4 times greater. He claimed that thimerosal in vaccines had caused autism, when several studies had shown that it hadn’t. Kennedy wrote that I had defended mercury in vaccines because the rotavirus vaccine on which I was a co-inventor was “laced with thimerosal.” But the rotavirus vaccine, which was licensed one year later, never contained a preservative. I called a senior editor at Rolling Stone who later retracted the article, as did Salon.

RFK Jr.’s most recent rant against me was delivered in a 3-hour episode on The Joe Rogan Experience, the most popular podcast in the world. Kennedy recounted his conversation with me. He told Rogan that to help him interpret studies evaluating the safety of mercury in vaccines, he had first called senior officials at the National Institutes of Health and the National Academy of Sciences. “And they kept saying to me I can’t answer that detailed question,” said Kennedy. “You need to talk to Paul Offit. Paul Offit made a $186 million deal with Merck. Odd to me that government regulators said that you should talk to someone in the industry.” First, I have never worked for a pharmaceutical company. At the time of the interview, our rotavirus vaccine wasn’t a licensed product. Second, although Fred Clark, Stanley Plotkin, and I are co-inventors and co-patent holders of the rotavirus vaccine, we are the intellectual property of Children’s Hospital of Philadelphia and the Wistar Institute. For all practical purposes, those institutions owned the patent, which they later sold to asset acquisition companies. I didn’t make a deal with anybody. And companies don’t pay $186 million for a product that isn’t a product yet. RFK Jr.’s statement about my $186 million dollar deal with Merck was a complete and utter lie. And it’s resulted in hate mail, physical altercations with anti-vaccine activists, and three death threats. One caller threatened my children. By falsely labelling me as someone willing to line my pockets at the expense of children’s health, RFK Jr. put both me and my family at risk.

RFK Jr. wasn’t finished: “It was weird to me that the top regulators in the country were telling me to go talk to an industry insider because we don’t understand the science. I talked to him, and I caught him in a lie. And both of us knew that he was lying.” “What was the lie?” asked Rogan. “I asked him why is it that the CDC and every state regulator recommends that pregnant women do not eat tuna fish to avoid the mercury but that the CDC is recommending mercury containing flu shots with huge boluses of mercury…And he said, ‘Well, Bobby, there are two kinds of mercury. There’s the good mercury and the bad mercury.’ [But] there is no such thing as the good mercury. I know a lot about mercury…Mercury was really an adjuvant that stimulates the immune system. Worse, mercury doesn’t kill bacteria like streptococcus or staph.”

Again, RFK Jr. was wrong. First, thimerosal isn’t an adjuvant, it’s a preservative. Second, thimerosal is bacteriostatic not bactericidal. It doesn’t kill bacteria; it prevents bacteria from growing. Finally, mercury is part of the earth’s crust, where it exists harmlessly in an inorganic state. However, due to rock erosion and volcanos, mercury is released onto the earth’s surface where it is picked up by bacteria and converted to an organic form: methylmercury. Unlike inorganic mercury, methylmercury can cross cell membranes and do harm. Indeed, methylmercury poisonings caused by industrial accidents in Japan and Iraq caused neurological damage in both adults and unborn children. But because mercury is in the earth’s crust, everyone has mercury in their bodies at levels well below those that are harmful. In the words of Paracelsus, a 16^th century physician, “The dose makes the poison.”

Ethylmercury (thimerosal), however, is not methylmercury. While methylmercury has a half-life in the bloodstream of about 70 days, ethylmercury has a half-life of seven days. So, it’s much less likely to accumulate and do harm. During the Rogan interview, RFK Jr. explained how he first came to believe that thimerosal was harmful. “In 2003, a CDC researcher named Pichichero did a study where he gave tuna sandwiches that were mercury-contaminated to children and then measured their blood…Then he injected the children with mercury from a vaccine and the mercury disappeared in a week. But where did it go?” Kennedy then referred to a study by Thomas Burbacher, who found that after injecting infant monkeys with thimerosal, mercury was detected in the brain where, according to RFK Jr. it “caused severe inflammation.” “And I told Offit about that study, and he was quiet and said there was a mosaic of other studies. I asked him to send them to me. But he never did and that’s the last I heard from him.”

Once again, RFK Jr. had misrepresented the facts. First, I am certain that if RFK Jr. had asked me to send him studies, I would have done it. Either I sent him the studies, or he never asked me to send them. In either case, RFK Jr. has said that he has taped our conversation. Great. Release the tape. Let’s hear what really happened. Second, Michael Pichichero studied infants as young as two months of age; he never fed them tuna fish sandwiches. Third, Pichichero concluded, “Administration of vaccines containing thimerosal does not seem to raise blood concentrations of mercury above safe values in infants.” Finally, it was not surprising that Thomas Burbacher found trace quantities of ethylmercury in the brain of infant monkeys injected with thimerosal, which can cross cell membranes. But RFK Jr. lied when he said that the mercury had caused “severe inflammation.” Burbacher didn’t report any evidence of inflammation, writing, “no serious medical complications were observed in any of the monkeys.”

RFK Jr. was probably right when he said that I had referred to a “mosaic” of studies supporting the safety of thimerosal in children. By the time that RFK Jr. and I spoke, several had already been published:

1)     Researchers in the United Kingdom performed a retrospective study to determine the relationship between thimerosal in infant vaccines and neurodevelopmental disorders. They found that thimerosal did not cause mercury toxicities.

2)     Researchers in the United Kingdom also performed a prospective study in children 6 to 91 months of age comparing thimerosal quantities in vaccines and cognitive and behavioral development. They found no evidence that thimerosal affected neurologic or psychological outcomes.

3)     Researchers also compared the prevalence and incidence of autism in California, Sweden, and Denmark following receipt of thimerosal-containing vaccines between the mid-1980s and late-1990s. They found that thimerosal was not associated with increased rates of autism.

4)     Researchers in the United States evaluated the relationship between thimerosal and neurodevelopmental disorders in 124,000 infants born between 1992 and 1999, finding no significant associations.

5)     Researchers in Denmark assessed the incidence of autism in children 2 to 10 years of age before and after removal of thimerosal from vaccines. Ironically, they found that the discontinuation of thimerosal in vaccines was followed by an increase in the incidence of autism. 

6)     Researchers in Denmark also evaluated the incidence of autism in children born between 1990 and 1996 who received either thimerosal-containing vaccines or thimerosal-free vaccines.  They found that the incidence of autism did not differ between the two groups.

Before our rotavirus vaccine was recommended by both the CDC and the World Health Organization for all infants in 2006, rotavirus killed about 2,000 children every day in the world. Our vaccine is estimated to save hundreds of lives every day. It’s the professional accomplishment of which I’m most proud. What, exactly, has Robert F. Kennedy, Jr. accomplished? Using the platform of a famous name, he has chosen to lie about vaccines and vaccine safety, no doubt putting children in harm’s way. And now he’s running for president of the United States.