DAY IN HISTORY-JULY 8, 1800

First Smallpox Vaccination in the U.S.

Dr. Benjamin Waterhouse inoculates his son Daniel

Components of a smallpox vaccination kit including the diluent, a vial of Dryvax® smallpox vaccine, and a bifurcated needle. Photo Credit: James Gathany, U.S. Centers for Disease Control. Public domain

While there seems to be a contemporary surge in anti-vax sentiment among some people, vaccinations against serious diseases have been proven safe and effective for centuries.

On July 8, 1800, Dr. Benjamin Waterhouse, who co-founded Harvard Medical School, inoculated his son Daniel, along with Samuel Carter, a household servant, with the smallpox vaccine. Waterhouse had become aware of experiments conducted by English physician Edward Jenner, who used cowpox material to successfully test a smallpox vaccine.

Waterhouse corresponded with Jenner and received some threads impregnated with cowpox material. He proceeded to test the vaccine on his son Daniel, sending him to a smallpox hospital ward and exposing him to the disease. When his son didn’t contract smallpox, Waterhouse inoculated three more children and another servant to prove the vaccine’s efficacy.

According to the Harvard Countway Library Center for the History of Medicine:

Waterhouse published the results of his work as A Prospect of Exterminating the Small Pox just a few weeks after the first vaccination experiments. He became a major advocate for vaccination, inoculating the public and supplying vaccine matter to other physicians and individuals, including President Thomas Jefferson. … In 1802, Waterhouse challenged the Board of Health to a public trial of vaccination. Six physicians along with Waterhouse vaccinated nineteen boys on August 16; later that fall, the volunteers were exposed to the smallpox virus. This trial was a complete success and the Board published a report strongly urging the public to take advantage of the procedure, attesting that “The Cow-pox is a complete preventive against all the effects of the Small-pox upon the human system.”

The U.S. Centers for Disease Control (CDC) say smallpox no longer occurs naturally; with no cases occurring since 1977, the disease has been eradicated, thanks largely to the smallpox vaccine.

Measles, on the other hand, has recently spread in the U.S. because of parental resistance to their children being vaccinated.

The measles vaccine, developed by Dr. John Enders, was first used in the United States in 1963. Dr. Maurice Hilleman introduced an improved vaccine in 1968, significantly reducing side effects. While widespread adoption of the measles vaccine had successfully eliminated measles by 2000, measles has made a comeback in the past few years.

The CDC reports over 2,000 confirmed cases of measles in 40 U.S. jurisdictions as of June 4, 2026 with 30 new outbreaks reported in 2026. According to Harvard Health Publishing:

It’s estimated that when 95% of people in a community are vaccinated, both those individuals and others in their community are protected against measles.

But nationally, measles vaccination rates among school-age kids fell from 95% in 2019 to 92% in 2023. Within Texas, the kindergarten vaccination rates have dipped below 95% in about half of all state counties. In the community at the center of the west Texas outbreak, the reported rate is 82%. Declining vaccination rates are common in other parts of the US, too, and that leaves many people vulnerable to measles infections.

Only 4% of the recent cases in the US involved people known to be fully vaccinated. The rest were either unvaccinated or had unknown vaccine status (93%), or they had received only one of the two vaccine doses (3%).

The evidence seems clear: When vaccines are universally adopted, disease outbreaks are highly preventable.

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