Depletion of immune effector cells alleviates SMA in semi-immune mice. (A) Parasitemia and (B) Hb levels, in phagocyte-depleted semi-immune mice (open symbols) and control semi-immune mice (closed symbols), normalized to the day of patency. n = 9 ± SEM. (C) Parasitemia and (D) Hb levels, in CD4⁺ cell–depleted (open symbols) and control (closed symbols) mice, normalized to day of patency. Mean individual minimal Hb levels for CD4⁺ cell–depleted (open bars) and controls (closed bars) are shown in the inset. n = 8 ± SEM for the CD4⁺ T-cell–depleted and n = 7 ± SEM for control groups. ^*P < .05; ^**P < .01; ^***P < .001.