The Roots of the Vaccine Panic

Deadly Choices: How the Anti-Vaccine Movement Threatens Us All, Paul A. Offit, Basic Books, 270 pages, $27.50

The Panic Virus: A True Story of Medicine, Science, and Fear, Seth Mnookin, Simon & Schuster, 429 pages, $26.99

Do vaccines cause autism or other neuro-developmental disorders? Scientists know that vaccines don't, but the idea lingers everywhere -- on talk shows and blogs and in conversations between parents and their child's pediatrician. It lingers because many people in this country and elsewhere think that vaccines just might not be good for us.

In two books that tell the story of the panic over vaccines, Paul Offit, chief of infectious diseases at the Children's Hospital of Philadelphia, and Seth Mnookin, a contributing editor at Vanity Fair, argue that bad people pursuing careers or fame or ratings or God knows what became purveyors of falsehoods that duped otherwise decent people into thinking vaccines could harm their children. That duplicity has led parents to make bad decisions -- not to vaccinate their children or to vaccinate them on a non-recommended schedule -- which turn out to be potentially deadly not just for their own children but for others.

How we got into this mess is the focus of both Mnookin's The Panic Virus and Offit's Deadly Choices. The casts of characters overlap, but the emphasis of each is different. Ironically, the journalist (Mnookin) focuses more on the malefactors of science, while the scientist (Offit) focuses more on the malefactors of the media. But each has a special distaste for the one closest to him: Mnookin for the journalist David Kirby, who helped sell the belief that mercury in vaccines caused an epidemic of autism, and Offit for the pediatrician Bob Sears, who willy-nilly invented a "new and improved" vaccination schedule.

As good as these books are, they don't help us fully understand why the anti-vaccine movement caught on. They are missing a sense of the desperation felt by parents when their children begin showing signs of autism. They also fail to appreciate the role that science itself has played in leading people to expect simple explanations of complex phenomena. Together, the desperation and the belief in simple answers have had deadly results.

Although the background story is complicated, the source of the vaccine panic is basically this: The prevalence of autism has increased spectacularly over the past 20 years, and although scientists can explain about 50 percent of the increase, they cannot account for all of it. As a result, a vast network of advocates, epidemiologists, scientists, junk-scientists, clinicians, quack-clinicians, celebrities, geneticists, expert witnesses for hire, snake-oil salesmen, playboy models, comics, charlatans, blog writers, and parents have entered the debate, developing their own or selling others' theories.

The two such theories highlighted in these books are that the mumps, measles, and rubella (MMR) vaccine is dangerous for children either because the measles-vaccine virus resides in the intestines of some children, leading to inflammation, leaky gut, and consequent developmental delays, or that the MMR vaccine contains thimeresol, a mercury-containing preservative, which leads to developmental delays. The first theory is biologically implausible, the product of crooked science conducted by Dr. Andrew Wakefield. The second has been falsified.

As both Offit and Mnookin note, the idea that vaccines are dangerous is not a new belief. It has been around for as long as vaccines have existed. Offit is clearest in explaining the underlying paradox: The belief that vaccines are bad for us is enhanced by their success. Men and women in their 50s and younger have no real memory of polio. Their children and grandchildren have had no experience with measles or rubella. As kids, my generation used to fear tetanus, which we were sure led to slow starvation because our jaws would lock shut midsentence, but I haven't met any children with this phobia in decades. I vividly remember my daughters' disbelief when reading Little House on the Prairie that Mary could go blind from scarlet fever.

All these obscure diseases have, like the bubonic plague, been banished to faraway places or distant pasts, and people in the United States have forgotten all about them. So they have naturally forgotten that these diseases can also lead to blindness, paralysis, brain damage, or death. Offit is brilliant at pointing out the absurdity of anti-vaccine activists' argument that vaccines are superfluous because they prevent us from catching diseases that people no longer catch.

In the history of the eradication of the "diseases of childhood," vaccines have played a role. They have not played the leading role in lives saved. Long before the first baby was jabbed with the diphtheria-pertussis-tetanus (DPT) or the MMR vaccine, mortality rates for diphtheria, whooping cough, and measles had steadily declined. In 1900, the death rate from diphtheria was 40.3 per 100,000. For whooping cough and measles, it was 12.2 and 13.3 per 100,000, respectively. By the end of World War II, all three were around 1 in 100,000. The same declines can be observed for diseases for which we have no vaccines.

Hygiene and improved nutrition are the real heroes in the war against disease, though neither Offit nor Mnookin points this out. It would make their credible arguments more credible if they didn't claim vaccines saved the world all by themselves. But both authors do stress that what vaccines have done is as remarkable as nutrition and hygiene reducing the mortality rate by 500 percent; in some cases vaccines have reduced the rate to essentially zero -- which is why people no longer fear the diseases that used to kill children. Instead, they fear vaccines.

If parents want to be fearful, they should fear unintentional injuries, which account for as many deaths of 1- to 4-year-olds as the next six leading causes combined. Or they can fear obesity. But as with the link between smoking and cancer, it is hard to see the link between gulping down a few donut holes and chronic illness later in adulthood. In contrast, many parents see a direct link between vaccination and autism. In fact, some even saw the link before it could have happened. Jenny McCarthy, for example, is reported by Offit to have asked her son's pediatrician right before her son was given the MMR vaccine, "That's the autism shot, isn't it?"

Human-interest stories abound in both books. All of the leading culprits in fear-mongering about vaccines appear so sneaky and craven that the reader wonders what could possibly motivate them aside from fame and fortune. True believers, though, are often motivated by their belief even if the belief makes no sense (to us). Deeper insight into the worlds of others comes from recognizing this fact. Neither book, however, despite nods in this direction, gets quite deep enough.

The MMR vaccine is routinely given to children in the United States when they are between 15 and 18 months old. At 15 months, most children toddle well, use three or more words regularly, and laugh at funny things. Some can sing, and a few can walk up stairs and walk backward. Two months later, most toddlers have doubled their word use, climb around and explore their environment, and enjoy imaginary games. They also know how to throw a tantrum when they are frustrated, respond to simple directions, play with toys, and stack a few blocks. As every parent knows, these are fantastic developments, but seen in this aseptic light, they are pretty modest achievements.

Many children with autism will miss these milestones. Even so, many children who appear to their parents and even their pediatricians to be developing normally but are later diagnosed with autism seemingly regress around age 2, losing their few words and social skills. Sometimes the regression is associated with a fever or seizures, sometimes not. Sometimes it appears suddenly, and sometimes it is only slowly pieced back together from parental recall.

Whether sudden or not, the regression is terrifying for parents. For many of them (but not all), the temporal simultaneity of the vaccine and the descent into autism cannot be just a chance event. It seems the vaccine caused their child's autism. As pointed out in the Vaccine Court Omnibus Hearings, beautifully described by Offit, the fact that experts can identify an array of developmental abnormalities in children from video taken well before their MMR vaccine, which neither parents nor pediatricians could see because they are not trained to do so, doesn't matter to parents looking for causes.

The strategy that parents are using to account for cause is no different from the theory that some autism epidemiologists have been using to account for increased autism prevalence. If all of a sudden, something happens (like increased autism prevalence), it cannot (ordinarily) be caused by something that happened afterward. So autism scientists have raced to identify the change over the past few decades that has led to the rising prevalence of autism.

Here, too, junk science competes with serious work. Because some articles have suggested that artificially generated electromagnetic radiation causes autism, parents have eliminated wireless computers in their house, disconnected alarm clocks, and thrown away their microwave. Because some economists have argued that autism is the result of "television watching due to precipitation" and that "seventeen percent of the growth in autism in California and Pennsylvania during the 1970s and 1980s is due to the growth of cable television," some parents have thrown away their TV or moved to less rainy climates (where their children can spend time outdoors, exposing themselves to overhead power lines, which have been variously associated in comparably questionable science with such diverse health outcomes as "breast cancer, decreased libido, fatigue, depression, birth defects, reproductive problems, heart disease, stress headaches, trouble sleeping, and many other symptoms. Yikes").

Yikes is right. The "science" here is as good as the science behind the idea that vaccines cause autism. Using the same methods, one could show that frozen yogurt, emo music, tofu, beets, sun-dried tomatoes, or anything else that has increased over the same time period as autism is a potential risk factor. The mistake here is to confuse correlated time series with cause.

It is also a mistake not to take this bad science more seriously. Modeling is important. Should it surprise us that if scientists are confusing correlated time series with cause that parents are doing it as well? That two things happen at the same time does not mean that one caused the other. The most famous example of this is the idea that storks bring babies into the world. Babies come from people. People live in houses and houses have chimneys and storks roost in chimneys so the more people the more babies, houses, chimneys, and storks. It is easy enough to lay the blame on malfeasant scientists and publicity hounds, but when ordinary scientists pursue news stories instead of properly specified models, things can go awry quickly. And in the case of autism science, they often have.

The bad science that causally associates vaccines with autism has led to dangerous changes in parental decision-making. Some children (not statistical abstractions) have died because they contracted whooping cough or measles. In California, rates of vaccine refusal (politely called vaccine exemption) have skyrocketed, threatening the loss of "herd immunity" in many communities. If a few children aren't vaccinated, they are unlikely to contract the disease, but if many are not, the disease may race through a community, threatening a mass epidemic.

Both books feature the real people whose children have been harmed or killed by diseases otherwise avoidable. So the decision to skip a vaccination differs from the decision to switch to battery-powered alarm clocks. Because the diseases that vaccinations prevent pass from person to person (except for tetanus), failure to vaccinate -- that is, free riding on the positive vaccination decisions of others -- is dangerous to everyone.

Mnookin makes an important argument about science: It is self-paralyzing. The problem is that it can never prove anything, just falsify the theories of others. Scientists can say that the idea that vaccines cause autism is not supported by the extant evidence but not that vaccines cannot possibly cause autism. They could, perhaps, in some unknown way in interaction with some unknown variables. And in that little space of enchantment reside the David Kirbys of the world who exploit the humility of science to create the doubt and uncertainty that allows conspiracy theories to flourish. Science needs to speak with a stronger voice to overcome both the assault on reason of anti-science crusaders and the indifference to reason of journalists who train the public to believe that every issue has two sides.

Both books are thrillers. They are true stories after all. The malfeasant doctors, publicity-seeking journalists, blinded activists, and confused celebrities do and say things that are truly shocking. Jenny McCarthy really does tell Oprah that her science is "mommy instinct," and Dr. Bob really does make up a new vaccination schedule.

Even so, telling a one-sided story is difficult. To fill out the pages, Mnookin travels down vaguely related rivers to discuss heuristics and cascades; Offit shows how the "self-interested" decision to refuse vaccination leads to a tragedy of the commons and then, most important, why the decision is only seemingly self-interested. Offit's book has a broader focus than Mnookin's. And Mnookin is a bit breathless for my taste. Offit is in the middle of the controversy. He is, after all, a character in the Mnookin book and reportedly requires bodyguards at talks. It seems as if some of the people who choose not to vaccinate their children feel so strongly about it that they want to harm Offit. They should read his book.

What should we say to the parents who choose not to vaccinate their children because they do not trust the Centers for Disease Control and Prevention, their doctors, or Big Pharma? Trust in science? As Mnookin argues, the discrediting of science has a long history and does not arise either from media insistence for balance or from government intervention. Still, while the sad story of the loss of faith in science didn't start with recent attacks by conservatives, their monkey business didn't help. In the meantime, as both books make clear, with respect to vaccine refusal, we have much more to fear than fear itself.