Fig 1. Kinetics of parasite levels during experimental blood-stage infection with P. falciparum or P. vivax.

Malaria-naive volunteers were infected intravenously at day 0 with freshly thawed cryopreserved P. falciparum or P. vivax infected erythrocytes. Parasite growth modeling using in silico analysis estimated that the P. vivax infecting dose was 15 times lower compared to the P. falciparum infecting dose (Khoury D & McCarthy JS, in preparation). Parasite levels in peripheral blood of infected volunteers were determined using consensus Plasmodium species-specific qPCR as previously described [12]. Blood samples used to assess immune responses were collected prior to infection. Graphs show mean data from 19 volunteers from three independent cohorts (P. falciparum) and 8 volunteers from four independent cohorts (P. vivax); error bars indicate SD.