The Panic Virus
Page 14
Regardless of the relative harmlessness of ethylmercury, there was a troubling self-assuredness that underlay health officials’ blasé attitude to thimerosal’s potential risks, which echoed the complacency regarding the whole cell pertussis vaccine in the 1970s. Pharmaceutical manufacturers and immunologists at times acted as if the fact that vaccines had saved more lives than any other single invention rid them of the responsibility of ensuring that the vaccines already on the market were as safe as possible.
The trigger that finally led to a systematic examination of thimerosal came about almost by accident, as a by-product of broader concerns about mercury in the environment. In the fall of 1997, a Democratic congressman from New Jersey named Frank Pallone introduced the Mercury Environmental Risk and Comprehensive Utilization and Reduction Initiative (or MERCURI). In addition to monitoring mercury emissions from coal-fired power plants, Pallone’s bill would regulate waste from household items such as batteries and thermometers and require the military to curtail its use of the heavy metal. MERCURI never passed, but Pallone did insert a provision into the FDA Modernization Act of 1997 that called for a federal report on all mercury-containing food and drugs within two years.
The opportunity to review already licensed drugs was a rare one for the FDA. Unlike the Environmental Protection Agency (EPA), which uses newly developed diagnostic tools to reevaluate pesticides every ten years, the FDA typically operates on a “one and done” licensure model: A drug deemed safe when it’s introduced to the market is, for all intents and purposes, considered safe forever unless evidence to the contrary emerges. Thimerosal was formally approved for use back in the 1940s, and while it did receive a second safety review in 1976, the scientific understanding of toxicity had improved considerably since then. The use of the preservative had never set off any precipitous alarms, but health officials who spoke candidly had to admit that they simply didn’t know what the ultimate risks were.
The task of assessing mercury in vaccines fell to the FDA’s Center for Biologics Evaluation and Research (CBER). In December 1998, it asked all vaccine manufacturers to provide detailed information regarding their use of thimerosal. By the following April, the agency had determined the precise concentration of thimerosal in each of the vaccines that included it as an ingredient. Then it narrowed this list down to those that were recommended for infants, which left the two versions of the hepatitis B vaccine and some formulations of the DPT and Hib vaccines. After running the numbers, the agency realized that an infant whose parents adhered to the recommended vaccine schedule could receive anywhere from 0 micrograms (μg) to 62.5 μg of ethylmercury at each of his two-month, four-month, and six-month checkups, for a maximum combined total of 187.5 μg.
Unfortunately, the lack of federal guidelines for ethylmercury consumption made this figure almost impossible to interpret. The confusion was heightened by the fact that there wasn’t even a clearly defined level above which methylmercury exposure was cause for concern, with three separate federal agencies each setting distinct benchmarks tailored to their individual mandates: The FDA’s was the amount that was unsafe for prolonged consumption in food, the EPA’s was the amount that would trigger an investigation of mercury levels in the environment, and the Agency for Toxic Substances and Disease Registry’s was the amount that could cause illness in the most sensitive members of a population. What’s more, none of those figures was for methylmercury injected directly into the body. It was clear that 187.5 micrograms of injected ethylmercury was higher than the FDA’s limit for ingested methylmercury—but what, exactly, did that mean?
Confronted with this mishmash of incomplete science and inconsistent regulations, a consensus emerged that until further studies were conducted, the best course of action was to remove thimerosal from pediatric vaccines, both as a safety precaution and to guard against the country’s entire vaccination program being called into doubt. There was considerably less consensus on how to go about this, with opinions ranging from the immediate suspension of all thimerosal-containing childhood vaccines to maintaining the status quo while quietly phasing in thimerosal-free vaccines in the months and years to come. In an effort to break this deadlock, the FDA solicited input from outside experts. Included among those was Neal Halsey, the director of the Institute for Vaccine Safety at Johns Hopkins University. The issue had a special resonance for Halsey: He was wrapping up a four-year stint as chairman of the AAP’s committee on infectious diseases, and over the previous decade he’d been one of the strongest advocates for increasing the number of recommended vaccines to eleven for children under two years old. Now he learned that during that period the amount of thimerosal infants could potentially receive had as much as tripled. Halsey’s first reaction, he says, was one of disbelief. “There was no safety data looking at whether that was safe or whether there was evidence of long-term outcomes,” he says. “No one had done six-or seven-year follow-ups on those children, or even thought to do it. That’s the situation we were in.”
From the outset, Halsey was convinced there was only one way to proceed: In a series of meetings and conference calls from June 25 through June 30 that included at various times officials from the AAP, the CDC, the EPA, and the FDA; independent toxicologists; and representatives from vaccine manufacturers, Halsey argued forcefully for a public statement supporting the use of thimerosal-free vaccines for all infants younger than six months old. The concerns about the preservative would be public knowledge by the end of July at the latest—that was when the FDA was planning on sending letters about the issue to all vaccine manufacturers and to members of Congress—and, Halsey argued, from a PR standpoint alone they’d be well served by getting ahead of the news.
In retrospect, what is most stunning about the events that followed is the rapidity with which they occurred. Thimerosal had been an additive in vaccines for more than half a century. The FDA Modernization Act had given CBER two full years to conduct its review. And then, in the course of a handful of days in the summer of 1999, an ad hoc jumble of policymakers, doctors, scientists, and industry representatives held a series of frenzied meetings in locations chosen specifically because they allowed for a circumvention of public disclosure laws. Established protocols were thrown out the window; experts who had never been a part of public policy discussions threatened to go public if their recommendations were ignored; ultimatums were given and then withdrawn.
When those initial meetings failed to produce a consensus, the debate spilled over into a series of frantic phone calls and hastily written draft statements over the July 4 holiday weekend. At the last minute, Surgeon General David Satcher stepped in to broker a compromise over the particularly sticky issue of the thimerosal-containing hepatitis B vaccine, which was given at birth. (The AAP wanted to postpone the shot, while the CDC was more concerned about the consequences of delaying it.) Ultimately, Satcher decided the AAP’s stance was the one most likely to result in a unified front.
On July 7, only two weeks after many of the parties involved had first learned about the issue, the two organizations released coordinated statements. The CDC’s read as follows (the added emphases are mine):
The Food and Drug Administration (FDA) Modernization Act of 1997 called for the FDA to review and assess the risk of all mercury-containing food and drugs. . . . There is a significant safety margin incorporated into all the acceptable mercury exposure limits. Furthermore, there are no data or evidence of any harm caused by the level of exposure that some children may have encountered in following the existing immunization schedule. Infants and children who have received thimerosal-containing vaccines do not need to be tested for mercury exposure.
The recognition that some children could be exposed to a cumulative level of mercury over the first 6 months of life that exceeds one of the federal guidelines on methyl mercury now requires a weighing of two different types of risks when vaccinating infants. On the one hand, there is the known serious risk of diseases and deaths caused by failure to immunize o
ur infants against vaccine-preventable infectious diseases; on the other, there is the unknown and probably much smaller risk, if any, of neurodevelopmental effects posed by exposure to thimerosal. The large risks of not vaccinating children far outweigh the unknown and probably much smaller risk, if any, of cumulative exposure to thimerosal-containing vaccines over the first 6 months of life.
Nevertheless, because any potential risk is of concern, the Public Health Service (PHS), the American Academy of Pediatrics (AAP), and vaccine manufacturers agree that thimerosal-containing vaccines should be removed as soon as possible. Similar conclusions were reached this year in a meeting attended by European regulatory agencies, European vaccine manufacturers, and FDA, which examined the use of thimerosal-containing vaccines produced or sold in European countries.
The AAP’s statement echoed many of the same points, but it did so in language designed to be more colloquial. “Parents should not worry about the safety of vaccines,” it began soothingly. “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 the following days, the most palpable response was confusion. Pediatricians were given no guidance on how to explain to worried parents that a small, hypothetical risk was overwhelmingly outweighed by the consequences of catching potentially deadly diseases like pertussis or diphtheria. While the CDC had advised hospitals to suspend hepatitis B vaccines for newborns except in cases where the mother was hepatitis B positive, many hospitals suspended the shot altogether, either because they were unsure of how to interpret the new recommendations or because they decided what was best on their own. Regardless of the reason, the consequences included an untold number of infections and at least one death, of a three-month-old who died of acute liver failure brought about by hepatitis B.
But it was the seeming ambiguity and not the alternately pedantic and convoluted wording of both organizations’ statements that proved to have the most negative consequences in the years to come. When officials at the CDC wrote that there was “no data or evidence of any harm,” they meant to offer the strongest reassurance they could, given that they could never say definitively that thimerosal had no side effects—there was always the possibility that some piece of new evidence might emerge in the future. But to a public not well versed in the language of science the line read like an equivocation. Even worse was the AAP’s phrase “make safe vaccines even safer,” which came off as institutional doublespeak of the worst kind.
Of course, it’s unlikely that even the most mellifluously worded statements would have prompted the media to provide nuanced explanations or include necessary context. Barbara Loe Fisher, who was oftentimes identified in the press as a seemingly impartial “vaccine expert” and as the head of a parent advocacy group that fought for children’s health, was relied on by many reporters in need of a quick reaction to the move. (One Los Angeles Times article helpfully listed her organization’s contact information for those interested in learning more about the subject.) Fisher wasn’t the only vaccine opponent who passed herself off as impartial: A Denver Post story quoted at length from a “forceful statement” distributed by the “Association of American Surgeons” that read, “Federal vaccine policy results in the violation of informed consent, and is based on incomplete studies of efficacy and potential adverse effects of the vaccines.” The organization the Post was referring to—its actual name is the Association of American Physicians and Surgeons (AAPS)—is an extreme-right-wing group that openly derides “evidence based medicine” and has accused the AMA of emulating Mussolini’s National Fascist Party.
The overall tenor of the media’s coverage only fueled the conviction of those doctors and health officials who believed it had been a mistake to conduct scientific deliberations in public, especially before all the evidence was in. The most outspoken proponent of this view was Paul Offit, the Philadelphia-based pediatrician and vaccinologist. (Earlier that year, Offit had coauthored Vaccines: What Every Parent Should Know, the first of many books he’d write on the subject.) In support of his argument, Offit pointed to the quandary the CDC found itself in after “Vaccine Roulette” had linked the DPT vaccine with neurological damage. “At the time, there was no evidence disproving [the program’s charges],” Offit says. “Companies couldn’t say, ‘Look, here are the epidemiological studies, look at the children who did or did not receive the vaccine,’ in order to show that the incidence of seizures and mental retardation was the same in both groups.” By the time enough evidence had been collected to show that the fears were baseless, there was no way to undo the damage that had been done.
Now, Offit said, a similar situation was unfolding: Reporters were skimming over the differences between ethylmercury and methylmercury and news segments were leaving out the risks of curtailing vaccinations in favor of a more sensational narrative. It would have been better, he argued, to have simultaneously developed thimerosal-free vaccines and conducted studies into ethylmercury’s effects on children. If the preservative was shown to be harmless in the quantities that had been used, the news would barely register in the public consciousness. (There’s not a lot of pizzazz in a headline that reads, “Chemical Removed from Vaccines Years Ago Turns Out to Have Been Safe After All.”) If it was shown to have been potentially injurious, the government could truthfully say it had taken action as soon as it realized there was a potential problem.
Neal Halsey was among those who thought that Offit was being dangerously naive. “A congressman would have been the person who stood up there and said, ‘Look, here’s a problem and nobody’s doing anything about it,’ ” Halsey says. “What would the impact be on our public image if the public health authorities and the AAP, if we had learned about this and said, ‘Don’t do anything’? What would the public’s perception have been of those agencies and organizations responsible for recommending vaccines to children? We would have suffered an enormous credibility gap. . . . That’s where Paul Offit doesn’t get it. He simply doesn’t understand.”
In the months to come, the debate spilled into public view: That fall, Halsey published an editorial in the Journal of the American Medical Association defending the AAP and CDC. Offit responded with a letter charging that the groups’ recommendations “might cause some children to miss vaccines that they need.” Stanley Plotkin, a colleague of Offit’s who’d helped develop the rubella vaccine in the 1960s, wrote a response to Halsey’s piece that was even more to the point: “The editorial by Dr. Halsey presents a positive picture of the events surrounding the new recommendations for vaccines containing thimerosal; in my view, what happened was nothing less than a public health disaster.”
• • •
Even with the benefit of hindsight, it’s impossible to say whether Halsey’s or Offit’s position had more merit. On the one hand, the events of the past decade give credence to Offit’s fears about the ways in which the news would be received. On the other hand, a Republican congressman from Indiana named Dan Burton began holding hearings on the country’s immunization policies later that summer, and it seems likely he would have grabbed hold of the issue irrespective of what the AAP and the CDC had recommended. Ever since Burton was first elected to the House in 1982, he has shown a flair for controversial statements and actions that invariably resulted in minor media frenzies. In 1997, he staged a backyard demonstration in which he shot a pumpkin in an effort to prove that Clinton associate Vince Foster had been murdered by White House hit men—a demonstration that prompted Calvin Trillin to write, “He failed to realize that in humans other than himself what’s inside the head bears no resemblance whatsoever to what’s inside a pumpkin.”31 The following year, Burton’s release of falsified prison transcripts of former associate attorney general Webster Hubbell prompted Republican leader Newt Gingrich to shout, “I’m embarrassed for you. I’m embarrassed for myself, and I’m embarrassed
for the conference at the circus that went on at your committee.” Burton also had a long and antagonistic history with medical authorities and an uneasy relationship to scientific facts: He was so terrified of catching AIDS that he brought his own scissors when visiting the House barber and refused to eat soup in public.
When Burton began committee hearings on August 3, he announced that his interest in vaccines had been prompted by the experience of his granddaughter, who he said had been rushed to the hospital after receiving the hepatitis B vaccine, and his autistic grandson, who Burton claimed had been fine before he received multiple shots in one day. Up to that point, there’d been virtually no mention of autism in any of the stories about the thimerosal controversy; in fact, there hadn’t even been any studies linking methylmercury to autism. “There has never been strong or reasonable scientific evidence to point to a link between thimerosal and autism,” says Saad Omer, a vaccine specialist who teaches global disease epidemiology at the Johns Hopkins Bloomberg School of Public Health. “Even the people who advocated removing [thimerosal from vaccines], the Public Health Service, when they did that, they were not talking about autism.” That was about to change. As Burton vowed that day, “We are going to be beating on this issue as long as I am chairman of this committee.”