....of a doctor's smallpox inoculation practice. He wrote it up for the Royal College of Physicians -- anyway I got it from Project Gutenberg online, where I like to check their recent acquisitions. He was working his way through the reasoning of the scientific method, but still reliant on then standard practices like purging, cupping, and bleeding.
Some people came through with just scars on their arms, and were fine after several weeks. Others got much sicker, including one fellow who had a hundred pocks going, but he was also counted a success. Dr Dimsdale carefully noted the patients who apparently were already incubating smallpox when they sought an inoculation from him, because they quickly came down with the full blown "distemper" instead of following the expected course. He also noted those who came down with something else while sick from the inoculations: one fellow got pneumonia, and a woman had what sounded like a strep throat or even uvulitis. They both survived. In fact all his patients did.
Dr Dimsdale counseled against inoculating children under the age of two years, because infant mortality was already very high and he just didn't think it was worth the risk.
Smallpox had a high mortality rate, and an even higher rate of disfigurement, so this physician did a brisk business in his efforts to prevent it; his services were much in demand.
Which brings me by a circuitous route to today's anti-vaxxers. They are astoundingly ignorant. They have not seen what we have seen, nor have they been taught. I think obstetricians and pediatricians should have a hand in educating their patients, but that's a rant for another time.