The Clinical Core, based within the Vaccine and Infectious Disease Division (VIDD) at Fred Hutchinson Cancer Research Center (FHCRC), will provide relevant expertise in clinical medicine, human subjects research, vaccine trials, and human immunology in support of the scientific aims of the Collaboration focused on the prevention and control of malaria and HIV. In order to most efficiently support the diverse aims of Collaboration projects, the CC will utilize a variety of resources including: 1) archived samples (e.g., cryopreserved PBMC, serum, plasma) from study participants in relevant completed or ongoing clinical trials, which comprise the primary source of clinical samples for Collaboration projects; 2) newly obtained samples from existing clinical natural history and control cohorts and from specifically designed sub-studies to enable more comprehensive analysis within ongoing or planned vaccine or treatment trials; and 3) samples acquired through the clinical expertise of collaborating clinicians accomplished in the safe sampling of specialized immunological reservoirs (e.g., bone marrow; lymph nodes; mucosa) using minimally invasive procedures in human volunteers.