1. The document discusses various studies on HIV and AIDS. It examines how PCR techniques can detect HIV even in asymptomatic patients, and how HIV replicates poorly in macaque models due to species-specific differences in CD4 receptors and co-factors. 2. Accidental needlestick infections and transmission from dentists to patients are discussed as examples of HIV transmission. The depletion of CD4+ T-cells during clinical latency is also summarized, as HIV production outstrips the immune system's ability to replace cells. 3. The latency period allows the immune system to be depleted enough for opportunistic infections to take hold, as HIV remains latent in memory T-cells. Variability in clinical latency depends on viral mutations