Recent advances in the immunology, pathogenesis, and prevention of human immunodeficiency virus (
HIV) infection continue to reveal clues to the mechanisms involved in the progressive immunodeficiency attributed to
infection, but more importantly have shed light on the correlates of immunity to
infection and
disease progression. HIV selectively infects, eliminates, and/or dysregulates several key cells of the human immune system, thwarting multiple arms of the host immune response, and inflicting severe damage to mucosal barriers, resulting in tissue infiltration of 'symbiotic' intestinal bacteria and viruses that essentially become
opportunistic infections promoting systemic immune activation. This leads to activation and recruitment or more target cells for perpetuating
HIV infection, resulting in persistent, high-level viral replication in lymphoid tissues, rapid evolution of resistant strains, and continued evasion of immune responses. However,
vaccine studies and studies of spontaneous controllers are finally providing correlates of immunity from protection and
disease progression, including virus-specific CD4(+) T-cell responses, binding anti-bodies, innate immune responses, and generation of
antibodies with potent antibody-dependent cell-mediated cytotoxicity activity. Emerging correlates of immunity indicate that prevention of
HIV infection may be possible through effective
vaccine strategies that protect and stimulate key regulatory cells and immune responses in susceptible hosts. Furthermore, immune
therapies specifically directed toward boosting specific aspects of the immune system may eventually lead to a cure for HIV-infected patients.