Influence of Vaccination on Respiratory Coccidioidal Disease in Cynomolgous Monkeys

Abstract

Summary: Five of ten Cynomolgous monkeys (Macaca irus) died and two were moribund within 9 months after respiratory infection with 200 coccidioidal arthrospores. None of seven animals previously vaccinated with formalinized spheruleendospore elements of the fungus succumbed to the above dose but one vaccinated animal challenged with approximately 400 arthrospores died within a 7-week period. It was demonstrated that both early and late roentgenographic changes in the lungs were less extensive in the vaccinated group than in the control group and these observations were in accord with pathologic findings at necopsy. The etiologic agent was recovered from the lungs of all surviving animals but histopathologic studies suggested that the parasite was contained more effectively within lesions in the vaccinated monkeys.