HIV vaccine development and clinical trials

The magnitude of HIV pandemic has made the development of HIV vaccines an urgent biomedical research priority. Although the biologic problems in designing a vaccine for a chronic viral infection like HIV are formidable, there has been encouraging progress. More than a dozen first generation prophylactic HIV vaccine candidates have completed phase I human trials that have established the safety and immunogenicity of these products in adults. A phase II trial of two HIV subunit envelope vaccines in adults at high risk of HIV infection is underway in the United States, and preparations for phase III efficacy trials have begun. Preliminary studies are under way to evaluate the potential application of active and passive immunization for preventing vertical transmission of HIV. Because of the higher rate of HIV transmission and a more abbreviated time course to disease, it may be more efficient to evaluate the efficacy of HIV vaccines in HIV infected pregnant women and their offspring than in adults who are exposed sexually to HIV.