RUTHFULLY YOURS

Almost 8,000 cases of pertussis, better known as whooping cough, have been reported to California’s Public Health Department so far this year. More than 250 patients have been hospitalized, nearly all of them infants and young children, and 58 have required intensive care. Why is this preventable respiratory infection making a comeback? In no small part thanks to low vaccination rates, as a story earlier this month in the Hollywood Reporter pointed out.

The conversation about vaccination has changed. In the 1990s, when new vaccines were introduced, the news media were obsessed with the notion that vaccines might be doing more harm than good. The measles-mumps-rubella (MMR) vaccine might cause autism, we were told. Thimerosal, an ethyl-mercury containing preservative in some vaccines, might cause developmental delays. Too many vaccines given too soon, the stories went, might overwhelm a child’s immune system.

Then those stories disappeared. One reason was that study after study showed that these concerns were ill-founded. Another was that the famous 1998 report claiming to show a link between vaccinations and autism was retracted by The Lancet, the medical journal that had published it. The study was not only spectacularly wrong, as more than a dozen studies have shown, but also fraudulent. The author, British surgeon Andrew Wakefield, has since been stripped of his medical license.

But the damage was done. Countless parents became afraid of vaccines. As a consequence, many parents now choose to delay, withhold, separate or space out vaccines. Some don’t vaccinate their children at all. A 2006 study in the Journal of the American Medical Association showed that between 1991 and 2004, the percentage of children whose parents had chosen to opt out of vaccines increased by 6% a year, resulting in a more than twofold increase.

Today the media are covering the next part of this story, the inevitable outbreaks of vaccine-preventable diseases, mostly among children who have not been vaccinated. Some of the parents who chose not to vaccinate were influenced by the original, inaccurate media coverage.

For example, between 2009 and 2010 more than 3,500 cases of mumps were reported in New York City and surrounding area. In 2010 California experienced an outbreak of whooping cough larger than any outbreak there since 1947. Ten children died.

In the first half of 2012, Washington suffered 2,520 cases of whooping cough, a 1,300% increase from the previous year and the largest outbreak in the state since 1942. As of Aug. 29, about 600 cases of measles have occurred in the U.S. in 2014: the largest outbreak in 20 years—in a country that the Centers for Disease Control and Prevention declared measles-free in 2000.

Who is choosing not to vaccinate? The answer is surprising. The area with the most cases of whooping cough in California is Los Angeles County, and no group within that county has lower immunization rates than residents living between Malibu and Marina Del Rey, home to some of the wealthiest and most exclusive suburbs in the country. At the Kabbalah Children’s Academy in Beverly Hills, 57% of children are unvaccinated. At the Waldorf Early Childhood Center in Santa Monica, it’s 68%, according to the Hollywood Reporter’s analysis of public-health data.

These are the kind of immunization rates that can be found in Chad or South Sudan. But parents in Beverly Hills and Santa Monica see vaccines as unnatural—something that conflicts with their healthy lifestyle. And they have no problem finding fringe pediatricians willing to cater to their irrational beliefs.

These parents are almost uniformly highly educated, but they are making an uneducated choice. It’s also a dangerous choice: Children not vaccinated against whooping cough are 24 times more likely to catch the disease. Furthermore, about 500,000 people in the U.S. can’t be vaccinated, either because they are receiving chemotherapy for cancer or immune-suppressive therapies for chronic diseases, or because they are too young. They depend on those around them to be vaccinated. Otherwise, they are often the first to suffer. And because no vaccine is 100% effective, everyone, even those who are vaccinated, is at some risk.

Parents might consider what has happened in other countries when large numbers of parents chose not to vaccinate their children. Japan, for example, which had virtually eliminated whooping cough by 1974, suffered an anti-vaccine activist movement that caused vaccine rates to fall to 10% in 1976 from 80% in 1974. In 1979, more than 13,000 cases of whooping cough and 41 deaths occurred as a result.

Another problem: We simply don’t fear these diseases anymore. My parents’ generation—children of the 1920s and 1930s—needed no convincing to vaccinate their children. They saw that whooping cough could kill as many as 8,000 babies a year. You didn’t have to convince my generation—children of the 1950s and 1960s—to vaccinate our children. We had many of these diseases, like measles, mumps, rubella and chickenpox. But young parents today don’t see the effects of vaccine-preventable diseases and they didn’t grow up with them. For them, vaccination has become an act of faith.

Perhaps most upsetting was a recent study out of Seattle Children’s Hospital and the University of Washington. Researchers wanted to see whether the whooping cough epidemic of 2012 had inspired more people to vaccinate their children. So they studied rates of whooping cough immunization before, during and after the epidemic. No difference. One can only conclude that the outbreak hadn’t been large enough or frightening enough to change behavior—that not enough children had died.

Because we’re unwilling to learn from history, we are starting to relive it. And children are the victims of our ignorance. An ignorance that, ironically, is cloaked in education, wealth and privilege.

Dr. Offit is a professor of pediatrics in the division of infectious diseases and director of the Vaccine Education Center at The Children’s Hospital of Philadelphia.