Vaccines and methods of inoculation for conferring immunity to Cryptococcus infection are disclosed. Strains of Cryptococcus fungi, including Cryptococcus neoformans and Cryptococcus gattii, can be administered to a human or animal subject via inhalation. Cryptococcus fungi that can be used to confer immunity can comprise one or more mutations in genes that contribute to chitosan production, such as genes encoding a chitin deacetylase (cda), a chitin synthase (chs) and/or a regulator of chitin synthase (csr). Inhalation administration of heat-killed Cryptococcus harboring deletions in cda1, cda2 and cda3 genes can confer immunity. In a murine model system, inhalation administration of Cryptococcus neoformans harboring deletions in cda1, cda2 and cda3 genes conferred immunity against subsequent exposure to wild type Cryptococcus neoformans in 100% of test animals. Inhalation administration of heat-killed Cryptococcus grown under conditions leading to reduced chitosan production can also confer immunity.
