Monthly increases in CD4+ T-cell percentages in children with severe immunodeficiency at ART initiation were significantly greater than in children without severe immunodeficiency, both within the first 6 months (2.04 [SE: 0.11], p-value = <0.0001 vs. 1.60 per month [SE: 0.15], p-value = <0.0001; p-interaction = 0.02) and after 6 months of ART (0.30 [SE: 0.09], p-value = 0.001 vs. 0.075 [SE: 0.07], p-value = 0.28; p-interaction = 0.04) (Figure 1). Here, CD4 is linked to immunodeficiency disease.