Fig. 2

Aotus antibody responses to EBA-175 RII after immunization with DNA plasmids containing RII. Groups of three monkeys were immunized intradermally 4 times at time 0, 4, 8, and 24 weeks with pFVORII, pFVORII/P2P30, or VR1020 (empty plasmid). The Aotus monkeys were challenged with the homologous P. falciparum FVO strain two weeks after the 4^th immunization and sera were tested from approximately 3 weeks postchallenge. Open circles (●) represent individual reciprocal titers at an ELISA OD of 0.5. Solid diamonds (●) represent reciprocal geometric mean titers at an ELISA OD of 0.5. PI represents pre-immune sera and Pf represents postchallenge sera. Error bars represent standard error of the mean.