Recently I found myself on the outskirts of an antivaccine rally in my hometown, listening to a succession of ill-informed diatribes with a mixture of dismay and fascination.

As a pediatrician, I was baffled by scientifically baseless attacks on the substances that have tamed smallpox, polio and a host of other deadly and disfiguring diseases, at least in the developed world.

But as a historian, I found it even more bewildering to hear speakers claim that government-sponsored vaccines were a violation of the founding fathers’ design.

It is true that in their time there was no such thing as safe, standardized immunization. But even then, inoculation was used to quell smallpox, the deadliest scourge of the day. Such preventive public health measures framed the early days of our nation as tightly as the “unalienable rights” of life, liberty and the pursuit of happiness.