It is important to study persons vaccinated with candidate HIV-1 vaccines who have become HIV-1 infected for the following reasons. First, if transient HIV-1 infection is detected and then is effectively suppressed or cleared, it will be important to document the antigenic relationship between the breakthrough virus and the vaccine epitopes to attempt to answer questions about the specificity and breadth of the immune response and the determinants of immunity. A second reason is to gain a better understanding of vaccine-induced responses in those participants who are transiently or persistently HIV-1-infected compared to placebo recipients who become HIV-1-infected. If the vaccine does not prevent HIV-1 infection, it will be important to characterize the course of the disease as measured by longitudinal viral load measurements, CD4+ counts, and clinical symptoms. Understanding the breadth, magnitude, and specificity of the immune response in partially or fully immunized vaccinees after infection and the impact on clinical symptoms and disease progression can potentially result in valuable information for the subsequent design of vaccine efficacy trials and, ultimately, in consideration of potential effectiveness of HIV-1 vaccines.

Study visits occur at Days 0, 7, 14, 28, then at 2 months, 3 months, 6 months, and every 6 months thereafter. At these visits, patients are given a physical exam, blood is drawn, and a donation of genital fluids is requested at certain visits. Patients are asked to donate samples of either semen (men) or cervical secretions (women); viral load is measured and compared to the amount and types of virus in the blood. He/she may refuse to donate these genital fluids and still be eligible to remain in the study. Primary medical care or medications for HIV infection are not provided by this study.