My mother has a small scar on her shoulder—a mark from the inoculation of vaccinia, a special virus that protected people from the deadly and disfiguring disease of smallpox.

I do not have such a scar because, in 1979, WHO announced that smallpox was eliminated thanks to widespread vaccination.1

This is what my mother did for me, but she did not do it alone.

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In 1764, more than 250 years ago, in the face of sweeping smallpox epidemics, the future Founding Father and second president of the United States, John Adams, underwent the only available protection of that time: inoculation with a small amount of live virus. This procedure caused a minor case of the disease, promoting immunity. John Adams later ensured his child received the same protection.2

This technique had an interesting lineage. British royalty had learned about inoculation from Turkey to protect their children. Meanwhile, American colonists gained this knowledge from African traditions, exemplified by Onesimus, a Bostonian slave who introduced the practice to his community. Though inoculation was tough and dangerous then, it saved lives by reducing smallpox mortality rates to about 2%.3

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During the Revolutionary War, smallpox played a critical role. The disease caused a stalemate in Boston between George Washington and General Howe. Howe considered evacuating Boston due to widespread infection, while Washington hesitated to enter for fear of exposing his troops. Smallpox also devastated the Quebec campaign, where nearly 900 of 2,000 soldiers fell ill or died.

One member of Congress wrote, “Our misfortunes in Canada are enough to melt the heart of stone. The smallpox is ten times more terrible than the British, Canadians and Indians together. This was the cause of our precipitate retreat from Quebec.”5

Recognizing the grave threat, George Washington issued an order in February 1777 to Dr. William Shippen Jr. He directed the immediate inoculation of colonial troops. The procedure was to be carried out as quickly and secretly as possible, as soldiers would be temporarily unfit for duty after inoculation. Washington declared:

“Necessity not only authorizes but seems to require the measure, for should the disorder infect the Army in the natural way and rage with its usual virulence we should have more to dread from it than from the Sword of the Enemy. Under these circumstances I have directed Doctr Bond to prepare immediately for inoculating in this Quarter, keeping the matter as secret as possible, and request that you will without delay inoculate All the Continental Troops that are in philadelphia and those that shall come in as fast as they arrive.”4

This decisive action changed the course of history.

Hugh Thursfield, a British pediatrician, later concluded: “Washington’s smallpox-free army went from strength to strength… intelligent and properly controlled application of the only method then known of defeating the ravages of smallpox, which in the years 1775-76 threatened to ruin the American cause, was a factor of considerable importance in the eventual outcomes of the War of Independence.”5

The intelligent use of vaccination helped build America.

Monument to George Washington in Philadelphia.

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My mother’s generation benefited from a safer type of vaccine—Edward Jenner’s discovery of the vaccinia-based method, later perfected by countless modern scientists.

1. WHO. (December 1979). The global eradication of smallpox

2. Woody Holton. (2010). Abigail Adams

3. National Park Service (2014). Smallpox, Inoculation, and the Revolutionary War

4. National Archives. Founders Online. From George Washington to William Shippen, Jr., 6 February 1777

5. Hugh Thursfield. (1940) Smallpox in the American War of Independence. p. 314 and 317

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Read an interview with Dr. Peter Hotez in Everybeat Academic Magazine 2024