PROGRESS IN THE DEVELOPMENT OF AN HIV-1 VACCINE

Containment of the acquired immunodeficiency syndrome (AIDS) epidemic will require an effective human immunodeficiency virus type 1 (HIV-1) vaccine. Accumulating evidence suggests that such a vaccine must effic iently elicit an HIV-1-specific cytotoxic T lymphocyte (CTL) response. Nonhuman primate models will continue to provide an important tool fo r assessing the extent of protective immunity induced by various immun ization strategies. Although replication-competent AIDS viruses attenu ated for pathogenicity by selective gene deletions have provided prote ctive immunity in nonhuman primate models, the long-term safety of-suc h vaccines in human populations is suspect. Inactivated virus and subu nit vaccines have elicited neither CTLs nor antibodies capable of neut ralizing a wide array of patient HIV-1 isolates. Considerable effort i s now being focused on evaluating live vector-based vaccine and plasmi d DNA vaccine approaches for preventing HIV-1 infection both in animal model and human studies. Our growing understanding of the biology of HIV-1 and immune responses to this virus will continue to suggest impr oved vaccination approaches for exploration.