Thundering herd

DR BOB SEARS, a paediatrician from Orange County, California, does not like to call his patients “free-riders”. True, he specialises in treating vaccine-sceptics, those families who resent being told to immunise their children against nasty diseases, from measles to whooping cough. It is also the case that, as a trained doctor, he believes that immunisation works. He agrees that some scary illnesses have almost vanished in America because more than 90% of children are inoculated against them, creating a herd immunity that leaves diseases with few places to lurk. Yet he differs from many doctors in the conclusion that he draws from that success.

Precisely because most children are immunised, he tells parents that it is probably safe to skip or delay jabs for their offspring. This strategy amounts to “hiding in the herd”, he says delicately, as he sips a late-afternoon coffee near his surgery. Put another way, his patients worry more than most about possible side-effects from vaccinations, above all the (thoroughly discredited) claim that vaccines cause autism. Dr Bob—as he is known to fans of “The Vaccine Book”, his best-selling guide to “selective” immunisation—does not say that worried parents are right. He just thinks that, on balance, they can safely indulge their anxieties by “taking advantage of the herd all around them.” When pushed, he makes “no claim” that the alternative vaccine plans that he offers (involving fewer jabs, or jabs administered over a longer period than most doctors recommend) are safer. He concedes that if everyone refused vaccinations, some diseases would roar back.

What Dr Bob does like to say is that, right now, many parents are very upset. This is because state legislators recently passed America’s strictest vaccination law. This not only mandates a fixed regime of vaccinations for children who wish to attend public or private school. It also eliminates a parent’s right to a Personal Belief Exemption (PBE), a claim that they cannot vaccinate children for religious or philosophical reasons.

California’s PBE rules used to be among America’s loosest. Most parents took children for shots anyway. But clusters of “anti-vaxxers” grew steadily larger, belying statewide averages of 90% coverage rates. In some places, as many as a third of pupils have shunned vaccinations. Hotspots included granola-and-windchime counties around San Francisco. In one school with many Russian-speaking Pentecostals near Sacramento, more than half the pupils were unvaccinated. The cause has become a populist staple: when not being horrible about foreigners, Donald Trump, the property tycoon running for president, talks of vaccines triggering an “epidemic” of autism.

All this has consequences. In 2008 an unvaccinated boy from San Diego caught measles on a visit to Switzerland, infecting 11 others on his return (Dr Bob will not confirm or deny reports that the boy was his patient). In December 2014 some 117 people caught measles in an outbreak traced back to two Disney theme parks in Orange County. None died, which was lucky, for measles is a horrible virus. Far more contagious than Ebola or the flu, it kills 146,000 people worldwide each year. It can be caught in a bus, a shop or doctor’s surgery two hours after an infected person last sneezed there. Even in the rich world and with the best care, measles can cause brain-damage and deafness, and kills about one in 1,000 of those who catch it. Before vaccines, the disease killed roughly 450 Americans each year, most of them children.

Dr Bob accuses legislators of “using” the Disneyland outbreak. It was “quickly contained”, he says. Yet legislators passed draconian rules for school pupils anyway. He has, he says, “a little conspiracy theory”: schools are one of the few places where legislators can directly control children’s health care.

The herd has rights, too

Miles to the north in Sacramento, a very different paediatrician has a simpler explanation for the new law. Dr Richard Pan remembers his first encounter with measles, as a medical student in Philadelphia in 1991. Nine children died, in part because many poor families could not afford vaccinations. After a medical career in California Dr Pan was elected to the state Assembly as a Democrat in 2010. That year California saw a whooping-cough outbreak that killed ten victims. The problem Dr Pan confronted centred not on the urban poor but on affluent, internet-surfing parents refusing to immunise children. In 2014 he was elected to the state Senate, representing Sacramento. Weeks later measles hit Disneyland. He helped write a law to make parents vaccinate children. Medical exemptions are allowed for children with weak immune systems. Parents who still refuse must homeschool their offspring. The law passed, but not before Dr Pan and allies had endured threats and meetings at which activists blamed vaccines for a “holocaust” of harm.

Now the paediatrician-turned-senator faces a recall campaign. If opponents can gather 36,000 signatures they can force a special election. The anti-Pan coalition is eclectic. One organiser, Aaron Mills, sounds like vaccine sceptics in Europe. A longtime Democrat who works for the state’s fire service, he believes that pharmaceutical giants and doctors downplay the risks of vaccines and exaggerate their benefits, probably for profit. Another founder of the recall drive, Katherine Duran, denounces the vaccine law in distinctively American terms. She calls it a “theft of liberty”. In her telling, Dr Pan has betrayed his primary duty as a legislator: to defend individuals from government “tyranny”.

Reassuringly, most Californians side with the medical consensus. Support for the state’s new vaccine laws has been measured at 67% and Dr Pan is likely to survive his recall. High-profile outbreaks have shaken a state slipping into complacency, showing the vaccinated majority that their collective immunity is threatened by the science-averse and the simply selfish. Though Americans take individual rights seriously, the herd is fighting back.