Smallpox vaccination of US military forces dates back to 1812. Smallpox vaccine has been given to millions of Americans, including Service members during World War I, World War II, and into the 1980s.
In the United States, routine vaccination against smallpox ended around 1972 in most places. Military smallpox vaccination programs continued longer. In 1984, routine military vaccinations were limited to recruits entering basic training. Between 1984 and 1989, some service members were immunized but not others. In 1990, the Department of Defense discontinued routine vaccination of recruits.
Between December 2002 and January 2008 more than 1.4 M Service members received smallpox vaccination.