Changes in CD4+ T cell numbers as a function of viral replication and dissemination in the peripheral blood, in four groups of SIV-infected macaques during primary infection. (A) Protocol for SIV infection, evaluations, and the euthanasia of each animal. Each box indicates the group of macaques explored at the corresponding times. (B) Changes in absolute counts of total CD4+ T cells in peripheral blood. (C-D-E) Changes in viral RNA levels in plasma and viral DNA and 2LTR circle levels in PBMCs. Bold lines indicate the mean value (B-D-C-E).