IMMANUEL KANT has been on my mind as I’ve followed the national response to recent measles outbreaks. Kant, a German philosopher, emphasized the danger of a temptation we are all vulnerable to—the temptation to make special exceptions for ourselves. The person who acts against principles that she thinks others ought to follow becomes a kind of moral “free-rider,” attempting to benefit from public moral order without contributing to it.
The spread of disease among the intentionally unvaccinated highlights the free-rider problem faced by parents who seek exemption from vaccination.
Some people believe that leaving their children unvaccinated (or under-vaccinated) minimizes their children’s health risks. If everyone around them has been vaccinated, their risk of infection is indeed low. But when too many people decide to forego vaccination, “herd immunity” is lost and disease outbreaks occur.
In a public without herd immunity, the risks posed by disease far exceed the small risks associated with vaccination. In other words, free-riding does not work when everyone is doing it. Herd immunity does not require universal vaccination, but it does require vaccination of a sufficient majority.
Who should get to be in the minority that remains unvaccinated and yet retains protection from disease? This is who: Babies who are too young to be vaccinated, our elders who cannot mount a robust immune response to some types of vaccines, and cancer patients and people with compromised immune systems all clearly have a claim to be shielded by their neighbors’ immunity. The decision to ask for an exemption for one’s own healthy child is a morally risky decision, one that requires an honest examination of conscience.