The backlash against parents who refuse to vaccinate their children rose to a crescendo a few weeks ago after a not particularly large outbreak of measles began in Disneyland and spread to several states and Mexico. But just as excessive fear of vaccines is leading a small number of parents in some geographic pockets to not vaccinate or to pick and choose and delay vaccination rather than follow medically recommended schedules, some of the backlash against these parents is excessive as well. For example, there are calls to eliminate the right of parents to opt their kids out of mandatory school vaccination programs based on religious or philosophical grounds. Now the backlash against that backlash has begun, with predictable and potentially dangerous results.

Several states are considering elimination of the opt-out option (except for medical reasons). California, which has pockets of low childhood vaccination and where the recent measles outbreak was worst (126 cases out of a total of 142), is one. Another is Oregon, which has the highest statewide exemption rate for kindergarteners, at 7 percent. But the Oregon state senator who made that proposal has withdrawn it, after it provoked an entirely predictable firestorm of opposition from strident anti-vaxxers like Andrew Wakefield and Robert Kennedy Jr., and from a lot of other more moderate people who just don’t like the idea of government taking away parental autonomy.

The proposal to ban religious and philosophical exemptions is an understandable reaction to the fear of diseases like measles and whooping cough that certainly deserve concern. These diseases can do serious harm. In rare cases they can kill. But banning parental choice is an emotion-based overreaction that goes beyond what is necessary to manage the risk to the general public caused by parents refusing to vaccinate their kids. Worse, it’s an overreaction that may make things worse — by firing up and broadening resistance to mandatory vaccination programs in the first place.

The solution to under-vaccination of children need not entirely eliminate choice. It just has to make opting out harder, which will reduce the number of people exercising that choice. That will get enough kids vaccinated to achieve herd immunity, the level at which enough people are resistant to a disease that it can’t spread. For personal belief exemptions, government could require parents to provide a letter describing their beliefs, and evidence from their lives that they apply those beliefs to how they live. For religious beliefs, people should be required to submit a letter from their priest or rabbi or imam or spiritual leader specifying how their faith precludes vaccination (few do) and evidence from their lives that they are living consistent with those religious beliefs. (These standards are already applied in court cases when such conflicts get that far.)

Economic influence could also be applied. People who drive poorly, or who smoke, pay more on their insurance to cover the costs of those higher-risk behaviors. States can encourage insurance companies to do the same thing for the higher risk posed by unvaccinated kids. Charge parents who choose not to vaccinate their kids higher insurance premiums. It is entirely justified that government require insurers to do this. Communities pay enormous costs to control outbreaks.

And here’s a big one. Personal belief exemptions based on rejection of solid medical evidence about vaccine safety should be rejected outright. School systems have to set policy based on what medical experts recommend. People may disagree with what the evidence says about the minimal risks of vaccines, but school systems are simply not the venue for that fight.

 

Research suggests that making it harder to opt out discourages many from doing so. In some states that have recently made it harder, the opt-out rate has dropped. In Washington, it went down 25 percent simply by requiring parents to provide a note from a doctor saying they’d been educated on the issue. In Florida, Texas, and Minnesota, where the rules haven’t changed, but the administrative burden of opting out is higher, fewer parents do than in Connecticut, Wisconsin, and Missouri, where it’s easier.

So the evidence suggests that it’s not necessary to entirely eliminate the opt-out option to move vaccination rates toward herd-immunity levels. But as the excessive fear of the vaccines themselves demonstrates, when it comes to the perception of risk, evidence isn’t everything. Our perceptions of risk are shaped not so much by the facts alone as by how we feel about those facts, based on several instinctive and emotional characteristics. In general, we worry more about risks that are imposed on us by the seemingly selfish actions of others, like the risk imposed on the wider community by parents who don’t vaccinate their kids. And we worry disproportionately about risks that are all over the news, like measles, even though the scale of this one outbreak was tiny.

But as understandable as these risk misperceptions may be, when our fears don’t match the facts, our reactions can get us into trouble all by themselves. Excessive fear of vaccines creates risk, as outbreaks of measles and whooping cough around the world have shown. Excessive fear of vaccine resistance can also be dangerous. As Oregon has demonstrated, the outright elimination of parental choice can poison trust in government, which could potentially drive some parents still ambivalent about vaccination into the anti-vaccine camp.

Yes, it needs to be much harder for parents to opt their children out of vaccination. But as the backlash to the Oregon proposal has shown, in the name of civil liberty and in the interest of general support for government public health programs, including vaccination, limited choice must remain.