Resistance to challenge and macrophage activity in mice previously vaccinated with formalin-killed Cryptococcus neoformans.

Mice were vaccinated with formalin-killed Cryptococcus neoformans either intranasally, intravenously, or intraperitoneally. Resistance to lethal challenge and in vitro phagocytic activity of alveolar and peritoneal macrophages was studied. Increased resistance to lethal challenge was seen following vaccination by each of the three routes but increased phagocytic activity was seen only in alveolar macrophages from mice vaccinated intranasally.