CD4 and infection: To assess which of these models best describes infection dynamics we fitted each model to the time course of viral load and CD4+ T cell count in each macaque (an average of 43 time points over 224 days) and calculated the small sample Akaike's information criterion (AICC) of the best fitting parameter combination (Figure 4 and 5, and Figure S6 and Table S3 in Text S1).