Candidate HIV/AIDS vaccines: lessons learned from the World's first phase III efficacy trials.

Abstract

In 2003 the results of the first two efficacy trials of candidate HIV-1 vaccines will be available. The first the AIDSVAX B/B trial was started in 1998 in the USA Canada Puerto Rico and the Netherlands. The trial will conclude in late 2002 with initial efficacy results available in the first quarter of 2003. The second the AIDSVAX B/E trial was started in Bangkok Thailand in 1999 and will similarly have initial efficacy results available in late 2003. Each study is unique. The North American/European trial will determine the efficacy of AIDSVAX B/B a bivalent subtype B gp120 vaccine using MN and GNE8 antigens in preventing sexual transmission of HIV-1 in geographical areas where subtype B HIV is most prevalent. For this trial 5108 men who have sex with men (MSM) and 309 high-risk women have volunteered. The Thailand trial will determine the efficacy of AIDSVAX B/E a bivalent gp120 vaccine containing the MN and A244 envelope antigens from subtype B and subtype E viruses respectively against blood-borne infection (Fig. 1). This trial involves 2545 injecting drug users (IDU) mostly heroin addicts in Bangkok where both subtype B and subtype E HIV are prevalent. The road from initial pre-clinical and clinical results to phase III efficacy trials has been long and difficult. The purpose of this paper is to review the lessons that have been learned through the experience of conducting the first phase III HIV vaccine efficacy trials. (excerpt)