There is a broad heterogeneity of clinical outcomes after infection with Coccidioides (Cocci) ranging from asymptomatic infection to mild pulmonary disease (“Valley fever”) to a life-threatening, invasive disease called disseminated coccidioidomycosis (DCM). Everyone in the endemic areas is susceptible to this infection, but we have almost no ability to predict who will develop disseminated disease and lack an understanding of why they do so. With nearly 10K reported cases of Valley fever and 200 cases of DCM yearly in California, our state alone spends ~$1B yearly on coccidioidomycosis. Thus, there is an urgent need to better understand DCM to enable better prevention, diagnostics, prognostics, and treatments. Our team's long-term goal is to study the intersection between the virulence programs of Coccidioides spp that maliciously exploit defective immunity, and the dysregulation of genetic and immunological programs of innate and adaptive immunity that allow for severe disease to take hold. Our program will bring together a cohesive and multi-disciplinary team of immunologists, geneticists, computational biologists, fungal microbiologists, and clinicians. Combining deep expertise with synergistic goals will enable breakthroughs. Our consortium includes four Projects and three supporting Cores: Project 1 addresses the innate immune responses to cocci infection that go awry in the first stages of cocci infection; Project 2 addresses the adaptive immune responses to cocci infection that go awry in protecting the host from disseminated disease; Project 3 addresses the genomic basis of cocci disease, from common variants that underlie susceptibility due to ancestry to rare variants that disable host defenses; and Project 4 addresses the contributions of fungal virulence factors in enabling the organisms to evade host immune defenses in some individuals. Our program includes an Administrative Core (Core A) that facilitates communications between investigators, organizes meetings and finances, and runs the Developmental Research Program. We also propose a unified Clinical Samples Core (Core B) comprising two of the largest coccidioidomycosis clinics in California, and a Model Organisms Core (Core C) that will carry out all experiments requiring BSL3 safety measures. These Cores together empower the proposed projects by providing common reagents, human samples, tools, and expertise. Our proposed investigations have the potential to transform our understanding of invasive fungal infections and will restore hope for patients through new approaches to prevent, diagnose, and treat DCM.