Altruism in action: will parents vaccinate their children to protect other children?

As I’ve written before, childhood vaccination has two functions. It protects the child from disease. But it also protects other children by boosting what epidemiologists call “herd immunity.” That is the phenomenon under which, if a significant percentage of a population is immunized, those few who are not immunized are protected because the disease cannot find a foothold in the herd.

Pertussis, or whooping cough, is an example in which we actually rely upon herd immunity to protect those who are most vulnerable to getting severe disease — small infants — because they are too young to use the vaccine in them. So the willingness of nearly everybody to vaccinate their children is what protects vulnerable babies. When sufficient numbers of people refuse to do that, whooping cough returns with a vengeance, and the children who are most affected are those who are too young to get the vaccine. To put it another way, more than is the case for other vaccines, we give our children pertussis vaccine to protect others. It’s a form of altruism.

A recent study in Pediatrics, the journal of the American Academy of Pediatrics, considered the question of parent’s motivations in getting their children vaccinated. Although obviously the most prominent reason is to protect their children, parents were asked about if they regarded protecting others as also important. That is, is doing one’s part to keep the herd immunity up also important. The article was a review of other research in which parents had been asked that question. The answer was that anywhere from 30% to 60% responded that protecting others was a key reason to vaccinate. I find this result encouraging: around half of parents are well aware of this important reason to vaccinate, and are willing to make this contribution for the good of all.