Fig. 2

PfCyRPA adjuvanted with either GLA-LSQ, GLA-SE or GLA-Alum elicited in rabbits high IgG titers with in vitro parasite growth-inhibitory activity. ELISA readouts (means ± standard deviations) obtained with serial dilution of sera taken pre-immune and after each immunization are shown in a–d. Serum anti-PfCyRPA IgG ELISA endpoint titers of individual animals are shown in e–h, with lines representing the mean titer. In vitro parasite growth-inhibitory activities of purified total IgG from individual rabbit serum samples collected after the final immunization are shown in i–l. Dots represent duplicate replicates of two independent [³H]-hypoxanthine incorporation assays. For each individual rabbit IgG preparation, a four-parameter sigmoidal dose-response curve was fitted to the relationship between log₁₀ of the antibody concentration and percentage inhibition, and then used to interpolate IC₅₀ values. Purified IgG from non-immunized animals and the parasite inhibitory anti-PfCyRPA mAb c12 were used as controls (m). The mean ELISA IgG endpoint titers obtained after the second, but not after the third immunization were significantly higher in the adjuvanted immunization groups when compared to the unadjuvanted group (Additional file 1: Table S1)