In 1914, the first typhoid vaccine was licensed in the U.S. in 1914. Typhoid immunization was required of all U.S. service members beginning September 30, 1911. The U.S. Army became the first military organization in the world to make typhoid vaccination mandatory, and had the lowest typhoid fever incidence of any major combatant in World War I.

During the Spanish-American War, one-fifth of U.S. troops (mostly U.S. Army personnel) had typhoid fever, and over 1,500 persons died of the disease; some acquired the infection in U.S. training camps before going overseas. In the Anglo-Boer War, the British army lost more men to typhoid (8,225 deaths) than it did to wounds (7582 deaths).