With full FDA approval of the Pfizer COVID-19 vaccine, the Pentagon has announced that all active-duty troops will be required to receive the vaccine as soon as possible—a mandate to protect the health and readiness of the military that stretches back to the very first commander-in-chief, George Washington. His decision to inoculate the Continental Army against smallpox was among the most controversial of his career but not for the reason many assume, as Elizabeth Fenn detailed in Pox Americana, her groundbreaking book about the smallpox epidemic that “coincided almost perfectly with the American Revolution and took many more American lives than the war with the British did.”
The fledgling United States faced two foes in the Revolutionary War. One was the British. The other was Variola major, the virus that causes smallpox. The conditions of the war—people moving about and coming together in encampments, only to disperse and move about in new areas—were perfect for spreading the highly contagious Variola virus. Mortality rates were high, approaching 30 percent in some instances, and could soar even higher among troops that were exhausted, malnourished, or exposed to harsh weather.
Because smallpox was endemic in England, most of the British troops had been infected with smallpox as children, when it was least likely to cause death, and had acquired lifetime immunity. But the American troops were a different matter. Spread about a sparsely populated country, few had been exposed to Variola. The only part of the colonies with significant exposure to the virus, and therefore some degree of immunity among the population, was the more urban Mid-Atlantic region. Troops from the South and New England were almost wholly unprotected from the disease, which gave the British an incalculable advantage in the war as smallpox began to spread ominously in Boston almost simultaneously with the commencement of hostilities in the spring of 1775.
Inoculation against the disease by deliberately introducing contaminated material into an incision in the skin had been known and practiced since the early 1700s, when the process had been learned from enslaved people from Africa and from reports of its use in Asia. But it had long been controversial. First, controversy was stirred by fears that it was contrary to God’s will. When the Puritan minister Cotton Mather supported inoculation experiments in 1721, his house was firebombed. But eventually most of the controversy came from fears that doctors practicing inoculation would unwittingly introduce the virus into the local population.
It was a well-founded fear. The inoculation process took over a month as the virus incubated and then the patient fought what was hopefully a mild case of the disease. Patients were contagious throughout the process, and many people went about their business during this time. After Abigail Adams was inoculated in July of 1776, she proudly reported to her husband that she had attended church services almost every day. In 1767, a doctor named John Smith opened an inoculation practice in Yorktown and launched an epidemic that spread to Williamsburg, killing a number of college students. When two doctors tried to set-up a similar practice in Norfolk, local citizens burned their house down. As a result, in 1770 the House of Burgesses severely restricted the practice, as did a number of state legislatures.
Adding further fire to the controversy was the fact that inoculation was expensive, at between two and five pounds, which made it the purview of the well-off. Many of the elite men who attended the Continental Congress in Philadelphia, which was a hotbed of the disease, were already inoculated, including Thomas Jefferson, who had undergone the procedure ten years earlier, and Benjamin Franklin. People who couldn’t afford the procedure for their families resented that they might be exposed to the virus by wealthy people being inoculated. (Franklin was so committed to smallpox inoculation that he founded a charity hospital to inoculate the poor.)
The controversy created a quandry for Washington. By July 4, 1776, there had been three major smallpox outbreaks: one in Boston; one in Quebec, which had decimated American troops fighting there and contributed to their humiliating defeat; and one in the Virginia Tidewater, which had likewise decimated the African American soldiers mobilized to fight for the British by Lord Dunmore’s Proclamation. It was clear that smallpox would be a major variable in the war. Washington knew that inoculation would level the playing field with the largely smallpox-resistant British troops. But initiating a large-scale inoculation campaign risked spreading the disease throughout the army if any soldiers broke quarantine before their disease ran its course.
At first Washington decided that it was just too risky. He hoped that quarantining sick soldiers would halt the spread of the disease. But it spread relentlessly through Washington’s Morristown encampment in the winter of 1776-77, threatening to undo the army’s pivotal victories at Trenton and Princeton. Fear of the disease was so widespread that it was suppressing enlistment by Virginians and other southerners who had little resistance to the disease. Soldiers were so desperate to avoid smallpox that they were inoculating themselves in secret.
Finally, on January 6, 1777, Washington gave the order to begin inoculation of the troops. But three weeks later, he reversed the order, only to reinstate it on February 5. “The small pox has made such Head in every Quarter that I find it impossible to keep it from spreading thro’ the whole Army,” he wrote to John Hancock, president of the Second Continental Congress.
Despite the complexity of inoculating troops with the primitive procedure and the necessity of keeping it a secret from the British, lest they attack when a large portion of the army was incapacitated, the campaign was a huge success. “The Army,” notes Fenn, “had pulled off the first large-scale, state-sponsored immunization campaign in American history.” Especially in the all-important southern campaign and the crucial victory at Yorktown, the American troops’ immunity to smallpox proved critical. Fenn concludes that Washington’s difficult decision to inoculate the troops “must surely rank among his most important,” and it’s hard to disagree.