More than 100 people have now been infected with measles as a result of a multi-state outbreak linked to Disneyland. Public officials have been eager to respond, and now it seems like everyone’s talking about compulsory vaccination, and it’s becoming a politicized issue.

On one hand, I think it is a good thing that most public officials are affirming the scientific consensus by saying that vaccines are good for kids, good for adults, and good for public health. And it may be a good thing to call out anti-vaxxers for recent outbreaks. On the other hand, I do worry about the fact that vaccination is the subject of a public debate, insofar as that lends any credence to arguments that link vaccines to autism. I also worry that the politicization of vaccine policy will only isolate and encourage vaccine deniers.

But despite my reservations, on balance I think it is good for people to actively encourage vaccination. And it’s also important to note that even libertarians should support public policies that promote vaccination, not because they would promote public health but because vaccine-refusal is morally wrong.

Some arguments for vaccination requirements go like this: We already have a bunch of laws that tell people what to do for the sake of their health, and those laws are good, so why not also have laws in favor of vaccines? In general, I oppose the idea that public officials can interfere with people’s choices for the sake of public health. For example, I think that drug prohibitions, soda bans, and seat belt laws for adults are all impermissible policies. People are not liable to be interfered with simply because they are making an unhealthy choice.

But vaccines are different for two reasons. First, I don’t think we should presume that parents have rights to make medical decisions for their kids. Rather, children’s treatment should be determined by what is in the best interest of the child, and that means getting vaccinated. (Tim Dare has a nice paper on parental authority here.)

Second, people don’t have rights to harm other people, and that is what vaccine refusal is. As I say in a recent defense of compulsory vaccination policies:

Vaccine refusal harms and risks harming innocent bystanders. People are not entitled to harm innocents or to impose deadly risks on others, so in these cases there is nothing to be said for the right to refuse vaccination. Compulsory vaccination is therefore justified because non-vaccination can rightly be prohibited, just as other kinds of harmful and risky conduct are rightly prohibited. I develop an analogy to random gunfire to illustrate this point. Vaccine refusal, I argue, is morally similar to firing a weapon into the air and endangering innocent bystanders. By re-framing vaccine refusal as harmful and reckless conduct my aim is to shift the focus of the vaccine debate from non-vaccinators’ religious and refusal rights to everyone else’s rights against being infected with contagious illnesses. Religious freedom and rights of informed consent do not entitle non-vaccinators to harm innocent bystanders, and so coercive vaccination requirements are permissible for the sake of the potential victims of the anti-vaccine movement.

Or in other words, compulsory vaccination policies are in principle permissible because vaccine refusal is morally wrong.

Of course, not everything that is wrong should be illegal. Adultery is wrong, saying you will meet someone for lunch and then not showing up is wrong, but it would be even more wrong to make these things illegal. Here is a reasonable test. Some choices are morally wrong because they violate important rights and are significantly harmful. If legislating against these wrongful choices would not reliably violate other important rights, then public officials can enforce policies that prevent wrongdoing. In some cases, vaccine refusal will not be seriously wrong because the risks of transmission are avoidable or small, and the potential harm of infection is not that serious. But for serious, potentially fatal diseases that are highly contagious (e.g. measles) the case for compulsory vaccination is much stronger.

As I argue in the essay, we don’t need to posit that the state has any unique moral authority to enforce laws in order to justify such a policy. If someone is doing something that is morally wrong they are liable to be interfered with if interference is proportionate and effective at stopping the wrongdoing. You don’t have to be a statist to think that it is permissible to stop someone from assaulting another person. For example, here’s Ronald Bailey in Reason making a similar point.

I think some of the reactions against the idea of compulsory vaccination among libertarians and libertarian-types stems from doubts about whether any kind of government policy can be permissibly enforced, given what we know about officials’ propensity to act in ways that exceed their moral authority. But this suspicion conflates the principled justification for compulsory vaccination with practical concerns about its enforcement. Once again, the Onion probably put it best— people don’t have rights to decide which eliminated diseases come roaring back, so they don’t have rights to refuse vaccination.

tl;dr: Vaccinate your kids.