Researchers pored over weekly reports of deaths in London to get a centuries-long view of how and when smallpox outbreaks ravaged the city.
Left untreated, smallpox would kill 3 out of every 10 who were infected with it, and those who survived often lived with scars afterward.
https://www.cnn.com/2020/12/22/health/smallpox-death-rates-covid-wellness/index.html