A louse-feeder 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. Louse-feeders were human sources of blood for lice infected with typhus, which were then used to research possible vaccines against the disease. 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.