Even after a vaccine, smallpox took two centuries to eradicate

In supposedly unprecedented times such as ours, there are compelling reasons to turn to the history of medicine. For hope, that epidemics do indeed come to an end; for consolation, that the people of the past suffered even more than us; and for insight into how we could be doing better. The story of smallpox satisfies all three.

Imagine an airborne disease such as Covid-19, but one in four people who get it will die. It causes a fever, but also a rash which cloaks the body in disfiguring pustules that fuse into reptilian scales. It leaves its victims, if not dead, scarred or blind. Few agree about why this disease spreads, how the body defends itself, or which treatments work. Nobody has heard of antibodies. Louis Pasteur’s immunological discoveries are more than a century away. Among the quackery of the 18th century, strange reports emerge about how to avoid contracting this devastating disease: transpose pus from the spots of the sick into the arms of the healthy, provoking a milder illness, while giving protection against full-blown smallpox.