FIG 2.

Preexposure to malaria is associated with difference in prepatency and parasitemia after CHMI. Parasitemia after CHMI was determined by qPCR. The day of first parasite detection by qPCR after PfSPZ injection is shown for Dutch (D; gray circles; n = 9) compared to Tanzanians (T; gray squares; n = 21) (A) and for P. falciparum-seropositive (n = 12; black squares) and -seronegative (n = 9; white squares) Tanzanian volunteers (B). The parasite load (number of P. falciparum parasites per milliliter of blood) at the first day of qPCR-detectable parasitemia (C) and the time of first peak parasite density (D) are shown for P. falciparum-seropositive (n = 12; black squares) and -seronegative (n = 9; white squares) Tanzanian volunteers. Data are shown as median ± IQR. Groups were compared by a Mann-Whitney U test.