Smallpox is mentioned in one or two places on this blog, eg the death of Snooke's wife in 1766. An article here looks at the subject.
Apparently smallpox mortality peaked in London in the 1760s, before declining slowly, and then rapidly after 1800 (both as a proportion of burials, and as absolute numbers of burials reported in the London Bills). The rapid decline in smallpox burials after 1800 coincided with the widespread adoption of Jenner's cowpox vaccination method, and despite incomplete coverage and low levels of re-vaccination, vaccination programmes succeeded in reducing smallpox to a relatively minor cause of death by the beginning of civil registration in 1837. However, the cause of the slower decline in smallpox burial totals before 1800 remains obscure. The practice of inoculation (deliberate infection with attenuated smallpox virus to confer immunity) became popular in the 1760s with the introduction of a safer and more effective procedure (known as the ‘Suttonian method’). Razzell has argued that inoculation was widely practised from the 1760s and had a spectacular effect in reducing mortality, although he found little evidence of inoculation being practiced in London itself. It is also possible that smallpox underwent a natural decline in virulence, although the scanty case-fatality data that exist for England suggest the opposite.
NB When small pox swept into Princeton, New Jersey during the winter of 1757-58, Jonathan Edwards, newly installed president of the local college, was given a vaccine by a reputable doctor. Thirty-seven days later Edwards was dead. In those days matter was removed from a pustule and inserted into a small incision between the thumb and index finger. If all went well, the patient endured a mild case of the pox and lived a normal life without fear of catching the full blown disease. In Edwards’ case something went terribly wrong. At first all was normal. He came down with a mild case and appeared to be on the mend. Then the pox spread into his mouth and throat, making swallowing very difficult. he died March 22, 1758.
Smallpox was one of that era’s great scourges. Epidemics recurred at fairly regular intervals. One in six patients would die from the pestilence. The mortality rate dropped drastically among those who received inoculations.