Anti-vaccine sentiment: a mile wide but an inch deep


In the wake of the Disneyland measles outbreak, I wrote about what I believe to be the drivers of anti-vaccine sentiment: privilege, defiance and parental ego.

We have to confront anti-vax parents where they live — in their egos. When refusing to vaccinate your children is widely viewed as selfish, irresponsible, and the hallmark of being UNeducated, anti-vax advocacy will lose its appeal.

It turns out that it was even simpler than that. Anti-vaccine sentiment collapses nearly completely when it costs parents time or money.

[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]Anti-vaccine sentiment collapses as soon as a parental cost is imposed.[/pullquote]

That’s the take home message from Emily Oster’s piece in today’s NYTimes, After a Debacle, How California Became a Role Model on Measles:

Data from a county-by county analysis shows that in many schools with the lowest vaccination rates, there was an increase of 20 to 30 percentage points in the share of kindergartners vaccinated between 2014 and 2016. One law changed the behavior of impassioned resisters more effectively than a thousand public service announcements might have.

That law was California SB 277 and it barred unvaccinated children without medical exemptions from public and private schools. For parents, it suddenly imposed a personal cost to anti-vax sentiment; the price for belief in pseudoscience became the need to homeschool your children. Vaccine rejection collapsed, especially in schools where anti-vax sentiment was driven by privilege, defiance and parental ego.

At the Berkeley Rose School, in Alameda County, only 13 percent of kindergarten students were up to date on vaccinations in 2014…

In the Berkeley Rose School, a private Waldorf school, all of the unvaccinated students (87 percent of the kindergartners) had personal belief exemptions…

By 2016, 57 percent of entering students were vaccinated — a huge change, and that was only in the first year of the law.

When there was apparently no personal cost to refusing vaccination, 87% of the parents refused. As soon as a cost was imposed, the refusal rate was immediately cut in half to 43%. No doubt it’s been cut further still in the past year.

The same thing is happening in Australia with the “No Jab, No Pay” policy.

As the Washington Post reported:

…[A] year ago, the country’s leaders took action. They launched the succinctly titled No Jab, No Pay campaign, which said simply — if you don’t vaccinate your kids, we’re not going pay out the customary $11,500 child-care welfare credit to you. “Conscientiously objecting” on nonmedical grounds wasn’t an option anymore. And all parents had to report their kids’ status to the centralized Australian Childhood Immunisation Register. Parents were given until March 2016 to get their children on track.

…[A] year in, it looks as though the program has had some success. Because of the policy, 200,000 more children received their vaccinations.

When there was apparently no personal cost to refusing vaccination, the parents of more than 200,000 children refused. As soon as they were hit in the pocketbook, the refusal to vaccinate evaporated.

In both California and Australia, anti-vaccine sentiment was a mile wide but only an inch deep. Anti-vaccine sentiment never really reflected fear of vaccine harm; it was just a status symbol among the privileged. It collapsed as soon as a parental cost was imposed.

As Oster notes, regarding California:

When SB 277 was passed, people worried about the possible effects: Would children be pulled out of school? This concern was misplaced. Over all, there has been no change in enrollment, even in schools with the lowest vaccination rates in 2014. People worried that parents would substitute (fake) medical exemptions for belief exemptions. This did happen, a little, but not nearly enough to offset the increases.

In the end, the effect of the law was simple: More children were vaccinated, and the risk of disease outbreaks has gone down.

What does this tell us?

It tells us that anti-vaccine sentiment doesn’t represent principled opposition to vaccines.

If parents truly thought that vaccines were harming their children, barring those children from public and private schools (California) or reducing the child care tax credit (Australia) would have almost no impact on vaccination rates. Parents, fearing serious injuries to their children, would simply homeschool them or do without the tax credit. But when the rubber hits the road — when refusing vaccines imposed a cost on them — parents decide they aren’t really that worried about vaccines after all.