- Antiretroviral (ARV) naïve. Participants will be classified as ARV-naïve if they meet any of the following criteria: 1) No ARVs for ≥ 6 months and never taken HIV medications for ≥ 30 consecutive days, 2) Females that only took ARVs during pregnancy and have been off ARVs for ≥ 6 months prior to enrollment, or 3) Persons whose only exposure to ARVs was "monotherapy"(meaning they were taking only one class of ARVs) before the advent of highly active anti-retroviral therapy (HAART).