The goal of this protocol is to understand how human lymphocytes respond to HIV-1 antigens in the context of vaccination or infection. This protocol will support understanding of the immune response by providing a source of lymphocytes and serum from selected individuals to study in laboratory based investigations. Blood samples from individuals who have received an HIV-1 vaccine, individuals who are HIV-1-infected, and individuals who are HIV-1-uninfected are requested to: (1) test previously vaccinated volunteers for HIV-1 envelope-specific B-cell and T-cell immune activities, and (2) increase understanding of how the human immune system processes and responds to HIV-1 envelope proteins.