Plasma viral load and CD4⁺ T cell counts in the peripheral blood of ASIL-4 treated and untreated macaques. (A) Cell-free plasma viral RNA load of the treated and untreated macaques at multiple time points was determined by real-time RT-PCR by using standards covering 6 orders of magnitude. Viral loads are shown as viral RNA copies per milliliter plasma. (B) CD4⁺ T-cell profile in the control and AS IL-4–treated SHIV_89.6P–infected macaques. The absolute number of CD4⁺ T cells per microliter blood was calculated by multiplying the percentage of lymphocyte subset with the absolute number of lymphocytes per microliter from complete blood count.