Candidate HIV-1 Tat vaccine development: from basic science to clinical trials.

Over the past 20 years most of the efforts in HIV vaccine development have focused on sterilizing immunity by targeting the Envelope protein (Env). However, results from preclinical and clinical trials have been largely disappointing [1–11]. Therefore, current vaccine strategies are not only aimed at preventing virus infection but also at blocking virus replication and disease onset. In particular, the control of virus replication should provide protection from disease development and reduce virus transmission, halting the HIV epidemic. This objective may be achieved by targeting virus regulatory genes, which are expressed early after infection, are essential for virus replication and pathogenesis, and are more conserved among HIV clades. This approach may be effective for both preventive and therapeutic vaccine strategies [12–68]. In this article we review the characteristics of Tat and why it was selected for use in a vaccine. We also cite the lesson learned in the development of this anti-Tat vaccine for use in human clinical trials.