Participants in this study will attend only one screening visit and study visit and will be assigned to one of four groups based on viral load and CD4 count. Group A will consist of participants who have a CD4 count of 200 cells/mm3 or less and a viral load greater than 1000 copies/ml. Group B will be made up of participants who have a CD4 count of 200 cells/mm3 or less and a viral load of 1000 copies/ml or less. Group C participants will have a CD4 count that is greater than 200 cells/mm3 and a viral load that is greater than 1000 copies/ml. Participants making up Group D will have a CD4 count that is greater than 200 cells/mm3 and a viral load that is 1000 copies/ml or less.