A safe, effective and accessible preventive vaccine is our best long-term hope for the control of the HIV/AIDS pandemic. The first phase I trial of an HIV vaccine was conducted in the US in 1987. Since then, >30 candidate vaccines have been tested in over 60 phase UTI clinical trials, involving >8000 healthy human Volunteers. The majority of these trials have been conducted in the US and Europe, however, trials have also been conducted in developing countries (Brazil, China, Cuba, Haiti, Kenya, Thailand, and Uganda), including an ongoing phase III efficacy trial of a rgp 120 candidate vaccine in Thailand. The effort to develop and evaluate HIV vaccines must increase, especially in Africa. (C) 2002 Elsevier Science Ltd. All rights reserved.