Is Development of a Vaccine against Cryptococcus neoformans Feasible?

Cryptococcus neoformans, the predominant etiological agent of cryptococcosis, is an encapsulated fungal pathogen that can cause fungal pneumonia and life-threatening infections of the central nervous system (CNS) [1]. C. neoformans can be found ubiquitously throughout the environment [1]. Inhalation of airborne yeast or desiccated basidiospores typically results in asymptomatic disease or dormant infections; however, progression towards clinical disease commonly occurs in persons with severely compromised immune responses. Global estimates suggest that 1 million cases of cryptococcal meningitis occur each year, resulting in approximately 625,000 deaths [2]. Morbidity and mortality rates due to cryptococcosis are significantly higher in resource-limited settings and in individuals with impaired CD4+ T cell-mediated immune responses (reviewed in [3–5]). Current therapies are often rendered ineffective because of the development of drug resistance by C. neoformans, drug toxicity, and treatment cost. Thus, a need remains for a cost-effective approach to prevent cryptococcosis.