In May of 1980, the World Health Assembly declared the world free from smallpox. The disease that had killed millions of people every century for much of recorded history was gone (at least, outside of laboratories)—a triumph that began with English doctor Edward Jenner, who discovered in 1796 that a little bit of a similar virus from cows could protect humans. Cows are vacca in Latin, hence vaccination.
Jenner’s work reached the U.S. in part due to the efforts of a Harvard professor, Benjamin Waterhouse, who vaccinated his own family and exposed them to smallpox patients. But Waterhouse wanted to spread the word, so he wrote to an amateur scientist in Virginia, writes Steven Johnson for How We Get to Next. That scientist was Thomas Jefferson.
The two figured out how Waterhouse could send vaccines to Virginia for more testing. An account from the Thomas Jefferson Foundation notes that Jefferson had already had his children and some of his domestic slaves go through a more dangerous, existing inoculation process. For this new vaccine, the first trial subjects Jefferson chose were three more slaves:
The vaccination of fourteen-year-old Ursula (later Ursula Hughes), daughter of Bagwell and Minerva Granger, did not "take." In further experiments later that summer at Monticello, butler Burwell Colbert and blacksmith Joseph Fossett were the first to be successfully vaccinated.
Jefferson had given 200 members of his extended family and neighbors the vaccine by August of 1800. He wrote to Waterhouse about the appearance of papules at the vaccination site:
As far as my observation went, the most premature cases presented a pellucid liquor the sixth day, which continued in that form the sixth, seventh, and eighth days, when it began to thicken, appear yellowish, and to be environed with inflammation. The most tardy cases offered matter on the eighth day, which continued thin and limpid the eighth, ninth, and tenth days.
Over the next few months, exposures to the virus showed that Jefferson’s vaccinated group was protected. Johnson notes, "Given the general quackery of most medical science during this period, the vaccine trials would have been an astonishing achievement for a full-time doctor," and Jefferson was "only moonlighting." The trial helped bring vaccination to the United States — Jefferson sent more vaccines to other parts of Virginia and Washington, D.C. He also instructed Meriwether Lewis to take some vaccine on the Lewis and Clark Expedition, the Thomas Jefferson Foundation reports.
Jefferson wasn’t the only founding father who championed vaccines. Benjamin Franklin was an outspoken, "eloquent advocate," of smallpox inoculation, reports the New York Times. Before Jenner made the breakthrough with cowpox, people would inoculate with the smallpox virus (or dried scabs of the pox) itself. This came with some danger of infection, but to Franklin, the promise was clear. After inoculating 72 Bostonians, Franklin observed that only two died, The Times reports. Franklin wrote, "Of those who had it in the common way, ’tis computed that one in four died."
Both Jefferson and Franklin had to argue with the early anti-vaccination movement. For Franklin, some of the discussion veered from the scientific into the personal: One of his sons died of smallpox at age 4, six years before Jenner discovered cowpox’s use. Some thought that little Franky had died after his father inoculated him with smallpox. But those were just ugly rumors. Franklin wrote in his autobiography: "In 1736 I lost one of my sons, a fine boy of four years old, by the small-pox, taken in the common way. I long regretted bitterly, and still regret that I had not given it to him by inoculation."