This alternate modelproduced results, with respect to HIV virulence evolution, equivalent to thoseobtained from the primary model calibration: ART initiation based on CD4 countresults in generally unchanged HIV virulence (mean SPVL relative to the no ARTcounterfactual), while ART initiation based on time since infections results inmoderate increases in mean SPVL, in scenarios of early initiation and highcoverage (Supplementary Figs. S9, S10 (time trends), and S11 (CD4 trends)). This evidence concerns the gene CD4 and infection.