Broadening inclusion of vulnerable populations in HIV vaccine trials.

The urgent need for a preventive HIV vaccine, as well as the complexities of its development, calls for timely and reinforced efforts to ensure vaccine licensure for use in a broad range of at-risk populations from the outset. Such an integrated strategy to HIV vaccine development should include infants of HIV-infected women, adolescents and injection drug users. A safe and effective HIV vaccine licensed for use in these populations, in addition to sexually active adults, would probably have the most timely and profound impact on the HIV/AIDS pandemic. Advanced clinical development of HIV vaccines in these vulnerable populations imposes particular scientific, operational and ethical challenges. Recent developments, including the early termination of a Phase IIb trial, present additional previously unanticipated challenges.