Vaccine Denial

Vaccine Denial
By Koren Shadmi

Progress is easy to take for granted. When I was a child in the late '60s, polio was history, measles was on the way out, and diphtheria and whooping cough were maladies out of old movies. Now these contagious diseases are making a comeback. Take measles, for instance. The disease used to infect 3 to 4 million Americans per year, hospitalizing nearly 50,000 people and causing 400 to 500 deaths. In 2000 a panel of experts convened by the Centers for Disease Control and Prevention proclaimed that measles transmission had been eradicated in the United States, except for imported cases. But that caveat is important. An unvaccinated 7-year-old from San Diego became infected with measles while traveling with his family in Switzerland and ended up transmitting the disease back home to two siblings, five schoolmates and four other children at his doctor's office - all of them unvaccinated. Whooping cough has also seen a resurgence: A school in the East Bay area near San Francisco was closed recently when some 16 students fell ill.

The reason for these incidents - and for recent outbreaks of polio - is that the percentage of parents vaccinating their children has fallen, perhaps because some parents see no point in warding off diseases they've never encountered. Religious or new-age beliefs may also factor into the decision: The San Diego outbreak spread in a school where nearly 10 percent of the students had been given personal-belief exemptions from the vaccinating requirement. The East Bay outbreak started at a school that emphasizes nature-based therapy over mainstream medicine; fewer than half of the students were vaccinated.

Why would parents refuse to vaccinate their children against dangerous diseases? Many are skeptical of modern science and medicine in general. (And it is true that most vaccines carry exceedingly tiny - but real - risks of serious illness or even death.) But I think most are responding to the widespread belief that vaccines are linked to autism. Recent studies have soundly dispelled that notion. And a simple glance at health statistics shows that autism cases continued to rise even after thimerosal, the mercury-based preservative widely blamed for the supposed autism link, was largely phased out of U.S. vaccines by 2001.

Nevertheless, these unsubstantiated fears have led some people to say that getting vaccinated should be a matter of individual choice: If you want to be protected, just get yourself and your children vaccinated.

Only it's not that easy. While the measles vaccine protects virtually everyone who is inoculated, not all vaccines have the same rate of success. But even if a vaccine is effective for only 70, 80 or 90 percent of those who take it, the other 30, 20 or 10 percent who don't get the full benefit of the vaccine are usually still not at risk. That's because most of the people around the partially protected are immune, so the disease can't sustain transmission long enough to spread.

But when people decide to forgo vaccination, they threaten the entire system. They increase their own risk and the risk of those in the community, including babies too young to be vaccinated and people with immune systems impaired by disease or chemotherapy. They are also free-riding on the willingness of others to get vaccinated, which makes a decision to avoid vaccines out of fear or personal belief a lot safer.

Of course it is very success of modern vaccines that makes this complacency possible. In previous generations, when epidemic disease swept through schools and neighborhoods, it was easy to persuade parents that the small risks associated with vaccination were worth it. When those epidemics stopped - because of widespread vaccinations - it became easy to forget that we still live in a dangerous world. It happens all the time: University of Tennessee law professor Gregory Stein examined the relation between building codes and accidents since the infamous 1911 Triangle Shirtwaist factory fire in New York and discovered a pattern: accident followed by a period of tightened regulations, followed by a gradual slackening of oversight until the next accident. It often takes a dramatic event to focus out minds.

The problem is that modern society requires constant, not episodic, attention to keep it running. In his book The Escape from Hunger and Premature Death 1700-2100 Noble Prize-winning historian Robert Fogel notes the incredible improvement in the lives of ordinary people since 1700 as a result of modern sanitation, agriculture and public health. It takes steady work to keep water clean, prevent the spread of contagious disease and ensure an adequate food supply. As long as things go well, there's a tendency to take these conditions for granted and treat them as a given. But they're not: As Fogel notes, they represent a dramatic departure from the normal state of human existence over history, in which people typically lived nasty, sickly and short lives.

This departure didn't happen on its own, and things don't stay better on their own. Keeping society functioning requires a lot of behind-the-scenes work by people who don't usually get a lot of attention - sanitation engineers, utility linemen, public health nurses, farmers, agricultural chemists and so on. Because the efforts of these workers are often undramatic, they are under appreciated and frequently underfunded. Politicians like to cut ribbons on new bridges or schools, but there's no fanfare for the everyday maintenance that keeps the bridges standing and the schools working. As a result, critical parts of society are quietly decaying, victims of complacency or of active neglect. It's not just vaccinations or bridges, either. A few years ago, I attended an Environmental Protection Agency Science Advisory Board meeting, and the water-treatment discussion was enough to make me think about switching to beer.

What do we do about this? To some degree, we have to do what the reformers of the 19th and early 20th centuries did: Hector people about the importance of paying attention to our society's upkeep. Alas, our main allies in persuasion will probably be the epidemics and other disasters that take place when too few pay attention. Sometimes, people have to trip and fall to be reminded that it's important to watch their step.

Shadmi, K. (2008, August). Vaccine Denial. Popular Mechanics, 185(8), 48-50.