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Smallpox inoculation in Boston

1721

African medical knowledge, tested during an epidemic

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Inoculation is giving a healthy person a small, controlled dose of infection to provoke a mild illness that protects against a lethal one. The Boston figures are among the earliest comparative mortality data in the history of medicine: around 2% mortality among the inoculated against 14% among the rest. The method was West African and also known in the Ottoman empire and China, reaching Europe by several routes at about the same time. It was contested and dangerous — inoculation gives a real infection — and was superseded by Jenner's vaccination in 1796. That the knowledge came from an enslaved man is documented by Cotton Mather himself.

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During a smallpox outbreak in Boston, an enslaved man named Onesimus explained that in his homeland people were protected by putting a little material from a sick person into the skin of a healthy one. The method was tried, and those inoculated died far less often.

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Part of Terra Saga — the story of Earth on a timeline. terrasaga.org · Last changed 2026-08-16