Immunization of mice against coccidioidomycosis with a subcellular vaccine.

In vitro-cultivated spherules of Coccidioides immitis were disrupted in a Braun homogenizer. The resultant wall fragments were separated from cell sap and endospores by centrifugation. Extraction of the walls with phosphate-buffered saline yielded a subcellular fraction that was immunogenic in mice. This fraction, which contained polysaccharide and protein, gave substantial protection against intranasal challenge with a usually lethal dose (1,000) of arthrospores, provided that it was administered with adjuvant.