An NIH institute that conducts and supports research to study the causes of allergic, immunologic, and infectious diseases, and to develop better means of preventing, diagnosing, and treating illnesses. NIAID is responsible for the federally funded, national basic research program in AIDS. It supports basic research, epidemiology, and natural history studies; blood screening tests; drug discovery and development; vaccine development and testing; and treatment studies, some directly and some through contracts and cooperative agreements with other institutions. It administers the Adult and Pediatric AIDS Clinical Trial Group (ACTG) network of testing units at hospitals around the country and the Community Programs for Clinical Research on AIDS (CPCRA), a community-based network of AIDS treatment research centers.