From Africa to Boston to London:
Smallpox Inoculation, 1721

Collaborating to Stop Infectious Disease


In 1721, a horrible smallpox epidemic was raging in Boston, carried to Boston on a ship returning from the Caribbean island of Salt Tortuga. The famous Boston minister Cotton Mather, who had watched three of his own children nearly die from smallpox, urged doctors to begin performing inoculations against the disease.

Mather had learned of the ancient practice of inoculation from his slave, Onesimus, who had been inoculated as a child in Africa. Mather was also aware of accounts from doctors in the Mediterranean who had seen inoculation. The process consisted of making a cut in the arm and dropping in a small amount of pus taken from a smallpox sore. Against hostile public opinion, Dr. Zabdiel Boylston agreed to try the technique, initially on his only son and two slaves. For a time, Dr. Boylston was unable to leave his farm (located near City Hall Plaza) due to the fury of his neighbors and colleagues. A lighted grenade was thrown into Cotton Mather's home.

But the results could not be denied. Before Dr. Boylston took action, the death rate was one in twelve: after inoculation, it dropped to one in forty! Two other doctors followed his lead, inoculating people in Cambridge and Roxbury. Successful inoculation experiments like this one eventually led doctors to develop vaccinations against the disease.

Mather wrote several reports about his experiments with Boylston which were published by the Royal Society in London in 1722. These, combined with the publications of Dr. Charles Maitland, an important London physician and proponent of inoculation, influenced the British royal family to undergo inoculation shortly after Mather's reports.

This daring experiment rested directly on the testimony of a man brought to the colonies as a slave. Eventually Cotton Mather freed Onesimus, not because he was instrumental in ending the epidemic, but because Mather considered Onesimus disobedient.