Figure 4.
Antibodies to Plasmodium falciparum circumsporozoite protein (PfCSP) measured 8 days after the second dose of P. falciparum sporozoite (PfSPZ) vaccine in vaccinees and normal saline controls in the 9.0 × 105 and 1.8 × 106 PfSPZ groups. Statistical analysis was done with Wilcoxon rank-sum test. Only P values <.05 are shown. Optical density (OD) 1.0 is the serum dilution at which the optical density was 1.0. Net OD 1.0 is the difference between the OD 1.0 eight days after the second immunization and the OD 1.0 prior to the first immunization. Abbreviation: ELISA, enzyme-linked immunosorbent assay.