The situation is strikingly different with HIV infection. For the most part, the natural immune response against HIV is completely inadequate and, once primary infection is established, fails to eradicate the virus. With uncommon exceptions, HIV disease is relentlessly progressive, and virtually no one has a spontaneous recovery. Unlike other viruses for which we have successful human vaccines, HIV quickly integrates itself into the DNA of the host cell, where, in some cells, it remains latent and essentially invisible to the immune system. Because latency is established very early — within days to weeks after opportunity wherein HIV remains vulnerable to eradication through the immune response is very short.1