Mice treated early during P berghei infection with 0.1 mg of either anti-CD41 mAb or anti-CD61 mAb are protected from severe P berghei malaria despite no detectable effects of the mAb treatment on parasitemia. The cumulative survival (A, C) and average P berghei parasitemia plus or minus standard deviation (SD) (B, D) in groups of 10 mice injected intraperitoneally on day 1 with 0.1 mg of either anti-CD41 mAb (A, B) or anti-CD61 mAb (C, D). • indicates anti-CD41 day 1; ▴, anti-CD61 day 1; ♦, rat IgG day 1; ▪, PBS day 1.