Understanding how neutralizing antibodies recognize HIV could aid the design of antigens that induce protective antibodies upon immunization. There have been several advances in this area of AIDS vaccine research, including structural elucidation of the core of two gp120 envelope glycoproteins and, more recently, determination of the structures of the broadly HIV-1-neutralizing antibodies b12, 2G12 and 2F5. The structures have enabled features governing the molecular interaction of each antibody with its epitope to be explored. For the antibody b12, this has resulted in the design of novel, tailored antigens aimed at inducing similar antibodies with equivalent neutralizing properties. This template-based approach to immunogen design shows promise as a means to engineer innovative AIDS vaccine candidates.