The long range objective of the proposal is to develop a vaccine for AIDS using as a basis anti-idiotypic antibodies. To achieve this goal the following tasks are proposed in Phase I: 1) to immunize mice with anti-HIV protein monoclonal antibody (MAb) which are capable of neutralizing viral growth in vitro and to select for hybrid clones which are producing anti-idiotypic antibody, 2) to immunize animals with the anti-idiotypic MAb and subsequently test for the generation of an immune response against HIV proteins, and 3) to determine if sera (anti-anti-idiotypic antibody) from immunized animals are capable of neutralizing HIV growth in an in vitro system. These results will determine the feasibility of utilizing anti- idiotypic antibodies to illicit a neutralizing response against HIV, and additionally will provide a basis for the development of an efficacious vaccine against AIDS.