1 in 13 residents– but the death toll was probably more, since the lack of sophisticated epidemiology made it impossible to identify the cause of all deaths. What was new, at least to Boston, was a simple procedure that could protect people from the disease. It was known as “variolation” or “inoculation,” and involved deliberately exposing someone to the smallpox “matter” from a victim’s scabs or pus, injecting the material into the skin using a needle. This approach typically caused a mild disease and induced a state of “immunity” against smallpox. Even today, the exact mechanism is poorly understoodand not much research on variolation has been done. Inoculation through the skin seems to activate an immune response that leads to milder symptoms and less transmission, possibly because of the route of infection and the lower dose. Since it relies on activating the immune response with live smallpox variola virus, inoculation is different from the modern vaccination that