Peering into the future: searching for answers to old and new questions about HIV/AIDS.

The success of the scientific quest to understand and treat HIV/AIDS since it was first identified in the United States nearly 30 years ago merits celebration; yet new, unexpected problems continue to develop as old ones persist. The significant benefits of combination antiretroviral therapy (cART) have contributed to the perception that the global or national threat posed by HIV/AIDS no longer exists. The persistent high levels of new HIV infections in the United States (56,000/year) and the world (2.7 million/year) underscore how much work remains to be done. This article highlights seven key questions that will define the scientific, clinical, and policy efforts to combat HIV/AIDS in the decades ahead.