Onesimus: The Slave Who Brought Inoculation To America And Saved The Country
Smallpox was a singularly devastating disease in the 18th century, killing up to 30% of those infected within mere days or weeks of contamination. The virus was unique to other epidemics, at least in how people understood the disease. It was obviously spread from person to person without any needed carrier, as in the case of rats and the bubonic plague. It took down every kind of person, "both male and female, both old and young, both strong and weak, both white and black." It was responsible for reducing the Native American population by over 50% in the centuries after European contact. Initially, there was little to be done about the killer disease. Their best guess at treatment was bloodletting, which was kind of the duct tape of 18th-century medicine, so usually, they were resigned to managing symptoms.
There was one long-practiced medical tradition that actually seemed to work, but the problem was getting people to agree to it. While inoculation was common knowledge in most of the Middle East and parts of Asia prior to the 18th century, it was largely written off in America. It was practiced almost exclusively by enslaved men and women whose credibility within the Western medical community was about what you'd expect it to be. Just to recap: bloodletting=good, vaccines=dumb.