Preparing developing countries for efficacy trials.

PURPOSE OF REVIEW

For the first time, Africa is poised to test the efficacy of two candidate vaccines. This raises many scientific, logistic, regulatory and ethical challenges for the continent. This review outlines recent developments relating to the epidemiologic, scientific, site development, and standard of care issues relevant to the conduct of these trials in developing countries.

RECENT FINDINGS

The AIDS epidemic in Africa has reached crisis proportions. Despite more than 20 years having passed since the discovery of HIV, there are no effective biomedical interventions. The testing of two adenovirus type 5-vectored HIV vaccine candidates for efficacy is crucial. These vaccines, which seek to elicit cytotoxic T lymphocyte responses, may not prevent infection, but may ameliorate infection and potentially prevent secondary HIV transmission. Efficacy of these vaccines may be impacted by the presence of pre-existing immunity to the vectors and the genetic diversity of HIV. Trials will be conducted in areas of the world with high HIV incidence, and special efforts should be made to enroll young women and adolescents. The development of clinical trial site capacity, technology transfer of immunogenicity assays to in-country laboratories, and expediting high-quality regulatory and ethical review and executing efficacy trials of the highest standard should be seen as paramount by donors, vaccine developers, clinical trial networks and developing world governments.

SUMMARY

HIV vaccine efficacy trials will soon be conducted in Africa.