THE REPORT, Vaccines and Autism, was issued in May 2004. After an exhaustive analysis of the available data, and after review by another independent panel, the committee concluded that there was no evidence to suggest the existence of any relationship between the two. “There really wasn’t any doubt about the conclusions,” McCormick said. “The data were clear.” The Institute of Medicine team attempted to review every important epidemiological study, whether published or not, involving hundreds of thousands of children in several countries. They set out with a clear goal: to discover what biological mechanisms involved in immunizations might cause autism. Yet, no matter where they looked or how they parsed the data, the central results never varied: unvaccinated children developed autism at the same or higher rate as those who had been vaccinated. The panel reported accordingly: “The committee concludes that the body of epidemiological evidence favors rejection of a causal relationship between the MMR vaccine and autism.”
The report also pointed out that the mercury contained within the preservative thimerosal, which had been used widely in vaccines for nearly seventy years, caused no apparent harm. Thimerosal had been a focus of special fury among anti-vaccine activists. By July 1999, however, two years before the IOM committee was convened, the preservative had been ordered removed from childhood vaccines as a precautionary measure. Vaccine manufacturers, under fierce public pressure, had agreed with the Centers for Disease Control and the American Academy of Pediatrics. “Parents should not worry about the safety of vaccines,” the academy said at the time. “The current levels of thimerosal will not hurt children, but reducing those levels will make safe vaccines even safer. While our current immunization strategies are safe, we have an opportunity to increase the margin of safety.” In other words, they decided it would be easier to get rid of the controversy than to explain it.
The decision, an attempt to placate parents, had no basis in scientific research, and set off a cascading wave of misunderstanding that persists to this day. Almost immediately, advocacy groups arose, filled with members who were convinced thimerosal had caused their children’s autism. “It was a decision that was made very abruptly,” McCormick, who had no role in making it, told me. “And with not very good communication between professionals and the public. Maybe they should have thought about what you might want to know to reassure people and that is a valid concern of parents. You know how this looks: ‘Last year you told me this was safer than blazes, and this year you are taking it out of the drinking water. Hmm . . . how can I possibly trust a word you say?’ ” At the time, little was known about the toxicity of ethyl mercury, the chemical compound in thimerosal—so almost all toxicology data about mercury in vaccines was inferred from research into a related molecule, methyl mercury, which is found in fish that we eat and is used heavily in industry. While everyone has tiny amounts of methyl mercury in their bodies, the less the better, particularly because it can take months to be eliminated from our tissues.
The IOM examined the hypothesis that vaccinated children would develop a particular type of autism, caused by mercury poisoning. Presumably those children would develop symptoms at a different age than those who were not vaccinated. Yet in an analysis of tens of thousands of children, no statistical age difference was discovered. Furthermore, if, as so many parents and advocacy groups still believe, there is a link between thimerosal and autism, one would assume that the number of children diagnosed with the illness would have decreased rapidly after the middle of 2000, by which time the preservative had been removed from nearly every childhood vaccine. Researchers in Montreal had a unique opportunity to test this hypothesis because in the 1980s Canada began to phase out thimerosal slowly over a decade. As a result, Canadian infants born in the years between 1987 and 1998 could have received nearly any amount of thimerosal in vaccines, from none to 200 micrograms, the latter being nearly the maximum daily dose that had been permitted in the United States. The Canadian team was able to study discrete groups and found that autism was most prevalent among children who received vaccines that contained no mercury.
Epidemiologists in Finland pored over the medical records of more than two million children, also finding no evidence that the vaccine caused autism. In addition, several countries removed thimerosal from vaccines before the United States. Studies in virtually all of them—Denmark, Canada, Sweden, and the United Kingdom—found that the number of children diagnosed with autism continued to rise throughout the 1990s, after thimerosal had been removed. All told, ten separate studies failed to find a link between MMR and autism; six other groups failed to find a link between thimerosal and autism. It is impossible to prove a negative—that a relationship between thimerosal and autism does not exist. While data can’t prove that, it has failed to find any connection between them in any significant study. Because of the strength, consistency, and reproducibility of the research, the notion that MMR or thimerosal causes autism no longer seemed to public health officials like a scientific controversy.
The panel attempted to be definitive: “The committee also concludes that the body of epidemiological evidence favors rejection of a causal relationship between thimerosal-containing vaccines and autism. The committee further finds that potential biological mechanisms for vaccine-induced autism that have been generated to date are theoretical only. The committee does not recommend a policy review of the current schedule and recommendations for the administration of either the MMR vaccine or thimerosal-containing vaccines.” The report suggested that people forget about thimerosal (which by then remained only in certain flu vaccines) and the controversy behind it. After all the research, thimerosal may be the only substance we might say with some certainty doesn’t cause autism; many public health officials have argued that it would make better sense to spend the energy and money searching for a more likely cause.
It didn’t take long for the findings, and the finality with which they were delivered, to generate reactions. Boyd Haley, professor of chemistry at the University of Kentucky and a witness who has often testified about his beliefs that mercury in thimerosal caused autism, was “amazed and astounded” that the IOM would conclude otherwise. Haley is also a prominent “amalgam protestor,” convinced that trace amounts of mercury in dental fillings cause Alzheimer’s disease, although no data exists to support that view. “The dismissal of thimerosal as causal to autism is outrageous!” he said. “It reflects a level of ignorance that is unacceptable for a scientific review committee. This is disgraceful and puts into question the very credibility of every oversight government authority in the United States. Exposure to thimerosal (mercury) causes a biochemical train wreck. I’m flabbergasted.”
His was far from a lonely voice of outrage. The day the 2004 report was released, Indiana representative Dan Burton erupted. “This research does a disservice to the American people,” he stated. Burton had long been a vociferous critic of the public health establishment and was well known for doubting many of the tenets of conventional medicine. “My only grandson became autistic right before my eyes—shortly after receiving his federally recommended and state-mandated vaccines,” he said in 2002. In an October 25, 2000, letter to the Department of Health and Human Services, acting in his role as chairman of the House Committee on Government Reform, Burton asked the agency’s director to force the Food and Drug Administration to recall all vaccines containing thimerosal. “We all know and accept that mercury is a neurotoxin, and yet the FDA has failed to recall the 50 vaccines that contain Thimerosal,” Burton wrote, adding, “Every day that mercury-containing vaccines remain on the market is another day HHS is putting 8,000 children at risk.” (The letter was sent more than a year after voluntary withdrawal turned exposure to thimerosal, which remained in only some flu vaccines, into a rarity.)
It would be easy enough, and to many people comforting, to dismiss Burton as a fringe figure—his active indifference to scientific achievement and his opinions on health matters are highly publicized and widely considered ludic
rous. If he is a fringe figure, however, he has unique power and many followers. The controversy not only continued, but intensified. Politicians have not shied away from using thimerosal as a public relations tool. On September 28, 2004, Arnold Schwarzenegger, governor of California, banned thimerosal-containing vaccines from his state for children and pregnant women. Other states soon did so as well.
No prominent American has spoken with more conviction about the putative dangers of vaccines or their relationship to autism than Robert F. Kennedy Jr. To him, the IOM report proved only that “the CDC paid the Institute of Medicine to conduct a new study to whitewash the risks of thimerosal,” he wrote in 2005, “ordering researchers to ‘rule out’ the chemical’s link to autism.” That year, Kennedy, whose environmental work for the Hudson Riverkeeper organization has often been praised, published an article in Rolling Stone (and on the Internet at Salon.com) called “Deadly Immunity.” It was, he wrote, “the story of how government health agencies colluded with Big Pharma to hide the risks of thimerosal from the public . . . a chilling case study of institutional arrogance, power and greed. . . . I was drawn into the controversy only reluctantly. As an attorney and environmentalist who has spent years working on issues of mercury toxicity, I frequently met mothers of autistic children who were absolutely convinced that their kids had been injured by vaccines.” He went on to say that he was skeptical until he read the scientific studies and looked at the data.
“Deadly Immunity” was a landmark in the history of science journalism, combining Kennedy’s celebrity star power with a stinging assault on reason and scientific fact. The piece was riddled with inaccuracies, filled with presumptions for which there was no supporting data, and knit together by an almost unimaginable series of misconceptions. Kennedy largely framed his piece around quotes taken from the transcripts of a scientific meeting where members of the Immunization Safety Review Committee had gathered to plan their work. Those quotes appeared particularly to damn Dr. McCormick, the committee leader. According to Kennedy’s article, McCormick told her fellow researchers when they first met in January 2001 that the CDC “wants us to declare, well, that these things are pretty safe,” and “we are not ever going to come down that [autism] is a true side effect” of thimerosal exposure. In other words, before the committee even began its work, Kennedy asserts, McCormick had closed her mind to the possibility of a connection between thimerosal and autism. It was exactly the kind of conspiracy people concerned about the effects of the MMR vaccine had feared.
The transcripts tell a starkly different story. It’s never hard to build a case with a partial quote; denialists do it every day, relying on fragmentary evidence and facts taken out of context. Here is what McCormick said: “I took away [from the previous day’s discussion] actually an issue that we may have to confront, and that is actually the definition of what we mean by safety. It is safety on a population basis, but it is also safety for the individual child. I am wondering, if we take this dual perspective, we may address more of the parent concerns, perhaps developing a better message if we think about what comes down the stream as opposed to CDC, which wants us to declare, well, these things are pretty safe on a population basis.”
As Harvey Feinberg, the former dean of the Harvard School of Public Health who is now head of the Institute of Medicine, pointed out at the time, the full quote was part of a discussion that focused on two issues: the need for parents to learn whether a vaccine was safe for an individual child who might be sick, and the public health community’s right to know if vaccines pose risks to a larger population. In fact, McCormick proposed that the committee consider addressing the parental concerns about the health of an individual child—in addition to the CDC’s concern about population-wide effects. McCormick’s approach, her intentions, and her words were the opposite of what Kennedy had implied. But Kennedy was just getting warmed up.
“The CDC and IOM base their defense of thimerosal on these flimsy studies, their own formidable reputations, and their faith that journalists won’t take the time to critically read the science,” Kennedy wrote in 2007 in the Huffington Post, which has emerged as the most prominent online home for cranks of all kinds, particularly people who find scientific research too heavily burdened by facts. “The bureaucrats are simultaneously using their influence, energies and clout to derail, defund and suppress any scientific study that may verify the link between thimerosal and brain disorders. . . . The federal agencies have refused to release the massive public health information accumulated in their Vaccine Safety Database apparently to keep independent scientists from reviewing evidence that could prove the link. They are also muzzling or blackballing scientists who want to conduct such studies.”
Kennedy has never explained why he thinks the public health leadership of the United States (not to mention its pediatricians) would wish to “poison an entire generation of American children.” He simply wrote that “if, as the evidence suggests,” they had, “their actions arguably constitute one of the biggest scandals in the annals of American medicine.” In his Rolling Stone article, Kennedy ignored the scores of other published reports, few of which were carried out by federal scientists, so that he could focus on the 2004 study produced by the Institute of Medicine, which he attacked mercilessly. Kennedy wrote that vaccines exposed infants to 187 times the daily limit of ethyl mercury determined by the Environmental Protection Agency to be safe. If true, they would all have died at once. Rolling Stone soon printed a correction—and then later corrected that correction. It is impossible to live on the earth and avoid exposure to mercury, but that amount would kill a grown man.
The actual figure was 187 micrograms, which is 40 percent higher than the levels recommended for methyl mercury by the EPA, a tiny fraction of the figure cited in Kennedy’s paper. Throughout the piece, Kennedy confused and conflated ethyl and methyl mercury, quoting as knowledgeable authorities the father-and-son team of Mark and David Geier, who have testified as expert witnesses in vaccine suits more than one hundred times—and who have been reprimanded repeatedly by judges who have dismissed them as unqualified to speak on the subject. (The father has an MD degree; David Geier holds an undergraduate degree in biology.) Their testimony has been tossed out of court on many occasions. One judge called Dr. Geier “intellectually dishonest,” and another referred to him as “a professional witness in areas for which he has no training, expertise, and experience.”
It is important to note that methyl mercury, the compound that is so dangerous when contained in fish and the product of industrial pollution, is not the mercury found in vaccines. The two forms differ by just one carbon molecule, which may seem insignificant. But as Paul A. Offit has pointed out in his indispensable book, Autism’s False Prophets, a single molecule can mean the difference between life and death. “An analogy can be made between ethyl alcohol, contained in wine and beer, and methyl alcohol, contained in wood alcohol,” Offit wrote. “Wine and beer can cause headaches and hangovers; wood alcohol causes blindness.”
Kennedy saw conspiracy everywhere he looked. He has attacked Offit himself, who along with colleagues invented a vaccine to combat rotavirus, which is responsible for killing two thousand children in the developing world every day. Those children typically die of diarrhea, and in June 2009 the World Health Organization recommended that the vaccine be made part of “all national immunization programs.” Kennedy, however, has referred to Offit, who is chief of infectious diseases at the Children’s Hospital of Pennsylvania, as “Dr. Proffit” and as a “biostitute” because he was paid for his research and received royalties from the sale of his invention. Offit, outspoken and unremitting in his support of vaccines, has become a figure of hatred to the many vaccine denialists and conspiracy theorists. He has been threatened with violence so often that congressional aides once warned him not to mention the names of his children in public. For several years, armed guards have followed him to meetings of federal health advisory committees (where he has been called a terro
rist), and employees in the mail room at Children’s Hospital routinely check packages or letters addressed to him that look suspicious and might contain bombs.
Meanwhile, data becomes increasingly informative, particularly with regard to the difference between the effects of ethyl and methyl mercury. One of the biggest concerns researchers have always had about mercury was how long it took to be eliminated from a child’s body. In 2008, a team of scientists at the Ricardo Gutierrez Children’s Hospital in Buenos Aires published a report that examined the issue in detail. Kennedy had written that “truck-loads of studies have shown that mercury tends to accumulate in the brains of primates and other animals after they are injected with vaccines—and that the developing brains of infants are particularly susceptible.” It turns out that mercury in vaccines can be tolerated in far larger doses than was previously understood. More than two hundred children were studied after receiving vaccines that contained ethyl mercury, which is still used routinely in Argentina. The children excreted half the mercury within four days, and their levels returned to normal eleven days after vaccination. In contrast, it takes roughly seventy days for the body to flush half of a dose of methyl mercury.
Denialism: How Irrational Thinking Hinders Scientific Progress, Harms the Planet, and Threatens Our Lives Page 7