Trial objectives and end points for measuring the efficacy of HIV vaccines.

In order to prove the efficacy of human immunodeficiency virus (HIV) vaccines, it will be necessary to do large-scale trials in populations at high risk of acquiring HIV infection. The choice of objectives and end points and their measurement will be key to the design of efficacy trials. To address these issues, the National Institute of Allergy and Infectious Diseases convened several workshops and discussions at national meetings. These discussions have concluded that many factors will contribute to the selection of practical primary objectives and end points for efficacy trials of HIV vaccines. For initial trials the objective of preventing the establishment of chronic infection is a reasonable choice, given the current state of knowledge. However, given the complexities of HIV and the acquired immunodeficiency syndrome, it will be important to collect data and evaluate other potential objectives and end points as well.