 During World War II (1941-1945), he worked at the Institute for Research on Thyphus in Lvov with Rudolf Weigel as the head and then at its Kraków branch.At that time he was involved in production of sera, vaccines and diagnostic kits.Immediately after the war, in 1946-1949, he worked at the Faculty of Bacteriology of the Jagiellonian University and the Laboratory for Production of Sera and Vaccines of the State Department of Hygiene in Kraków.