CD4+ T-cell percentage improved over the first 6 months of ART, increasing a mean of 1.6% per month, and then stabilized (Fig. 1E), such that the proportion with severe immunodeficiency decreased from 57.1% at ART initiation to 7.7% at 6 months on ART, and then remained at 0 to 6.6% until 36 months (Additional File 1 - Supplementary Table 4). Here, CD4 is linked to immunodeficiency disease.