Cages with typhus-carrying lice strapped onto a person's thigh. During World War II, feeding the lice with human subjects' blood was the only way to produce a viable typhus vaccine. A<unk>  was a job in interwar and Nazi-occupied Poland, at the Lviv Institute for Study of Typhus and Virology and the associated Institute in Kraków, Poland.<unk> s were human sources of blood for lice infected with typhus, which were then used to research possible vaccines against the disease. Research into a typhus vaccine was started in 1920 by parasitologist Rudolf Weigl. Weigl and his wife Zofia Weigl were some of the earliest lice<unk> s. During the Nazi occupation of the city,<unk> -feeding became the primary means of support and protection for many of the city's Polish intellectuals, including the mathematician Stefan Banach and the poet Zbigniew Herbert. While the profession carried a significant risk of infection,<unk> s were given additional food rations, were protected from being shipped to slave labour camps and German concentration camps, and were permitted to move around the occupied city. Typhus research involving human subjects, who were purposely infected with the disease, was also carried out in various Nazi concentration camps, in particular at Buchenwald and Sachsenhausen and to a lesser extent at Auschwitz.
Louse-feeder
Poster child
Pedestrian
Natural reservoir
Litter 
Post-hospitalist
Florida shuffle
Specific-pathogen-free