Typhus Vaccine

Typhus vaccines are intended to protect against different strains of typhus, including epidemic typhus (louse-borne), murine typhus (flea-borne), and scrub typhus, though as of 2025 the United States Centers for Disease Control and Prevention reported no commercially available vaccine for any of the three major strains. Early efforts focused on epidemic typhus, caused by the bacterium Rickettsia prowazekii and spread by lice: Hans Zinsser created one of the first such vaccines in 1932 using dead bacteria to provoke an immune response, while a Poland-based team led by Rudolf Weigl, including Ludwik Fleck, developed another that proved dangerous and costly to produce but effectively protected Belgian missionaries in China in the late 1930s. The need for a viable vaccine was especially acute during the Second World War, when typhus killed many soldiers; among United States troops the disease was controlled through a combination of available vaccines and pesticides against lice in crowded quarters. Typhus vaccine research has also been driven by concern that Rickettsia could be weaponized as a biological agent.