Thailand's Prime-Boost HIV Vaccine Phase III

The Thailand Ministry of Public Health will pursue the Prime-Boost HIV Vaccine Phase III Trial in Chon Buri and Rayong provinces, as planned. The Ministry and collaborating institutions remain confident in the scientific merit of the prime-boost vaccination concept and the combined immune response induced by ALVAC-HIV vCP1521 and AIDSVAX B/E, as demonstrated in Phase I and II safety and immunogenicity studies conducted in Thailand. The Ministry is aware of the comments made by 22 scientists in a recent Policy Forum in Science (D. R. Burton et al. , 16 Jan., p. [316][1]; see also the related Policy Forum on p. [961][2]). Although we welcome constructive input, we find the underlying premise of the Policy Forum flawed in that it uses data from efficacy trials of a single vaccine concept to predict the results of a prime-boost combination vaccine study. Only by conducting the trial will we be able to determine if the combination of two candidate vaccines will induce both cellular and humoral immunity and protect against HIV infection. Both the Screening Protocol and Vaccine Protocol of the Prime-Boost Study were reviewed and endorsed by Institutional Review Boards and Expert Committees in Thailand and the United States, and by the World Health Organization (WHO)/UN AIDS Programme (UNAIDS). Thailand's leading researchers, all of whom have international standing and extensive experience in AIDS vaccine studies, from the Faculty of Tropical Medicine, Mahidol University; the Armed Forces Research Institute of Medical Sciences, Medical Corps, Royal Thai Army; and the Thai AIDS Vaccine Evaluation Group, are involved in the conduct of this trial under the Ministry of Public Health. The Prime-Boost Study was carefully considered within multiple venues, including a special WHO/UNAIDS/Centers for Disease Control consultation on the impact of the lack of efficacy of the AIDSVAX trials in North America and Thailand, which concluded that “because of its independent scientific rationale,” it was appropriate to go forward with efficacy evaluation of the prime-boost combination. There is no such thing as wasting time or money in researching an AIDS vaccine. Regardless of the efficacy results, Thailand is benefiting from conducting this trial in several areas: Experience will be gained by its scientists and health workers, and its laboratory infrastructure and specimen archiving will be strengthened. Close collaboration has also been established with NGOs and community groups to plan and implement community engagement activities. Another important gain is the intensified HIV/AIDS awareness campaign around the trial, which directly benefits the local communities in Chon Buri and Rayong. Thailand intends to share knowledge and experience gained and lessons learned in conducting this large-scale community-based efficacy trial. Needless to say, if the vaccine is proven efficacious, other countries will benefit as well. The Ministry of Public Health will continue to strive to find the best preventive measure to stop the spread of HIV. It is the Ministry's responsibility to further reduce the yearly HIV infection rate in Thailand, which is currently 25,000. [1]: /lookup/doi/10.1126/science.1094620 [2]: /lookup/doi/10.1126/science.1096161