The apparent effectiveness of test‐and‐treat in increasing population‐level ART coverage among people with diagnosed HIV infection and increasing viral suppression among people on ART reinforces the decision by some countries, beginning in 2011, to adopt ART irrespective of CD4 cell count and immediate initiation of ART with simplified regimens; and it also reinforces the recommendations by the WHO and EACS in 2015 to adopt test‐and‐treat policies as a contribution to achieving the UNAIDS 90‐90‐90 target. This evidence concerns the gene CD4 and HIV infectious disease.