Groups of two animals were immunised twice (a) or three times (b) with antigen-loaded virosomes with (a) or without (b) pre-immunisation with inactivated influenza virus. Shown are serum anti-PfCyRPA IgG ELISA endpoint titers of individual animals and lines represent the mean titer. Two independent experiments yielded comparable results; representative data of a single assay is shown. c Immunoblot analysis of rabbit serum samples with blood-stage parasite lysate. Immune serum of a representative rabbit was pre-incubated with or without recombinant PfCyRPA protein competitor and subsequently added to cut strips. Immune serum was used at a dilution of 1:200 and the competitor at a concentration of 5, 0.5 or 0.05 μg/mL. Individual filter stripes of each blot derived from the same experiment and were processed in parallel. d Immune sera of rabbits were tested for parasite binding in IFA with in vitro cultured P. falciparum blood-stage parasites. Sera were diluted 1:1000 and representative examples are shown. The anti-PfCyRPA neutralising mAb c12 served as positive control. Scale bar, 5 µm.