Sixteen peptides -twelve targeted by ADCI positive antibodies and four controls-were used to immunize CB6F1 mice ( Table 2) . Eleven of them elicited an intermediate or high antibody response, four of which also recognized the parasite protein in infected erythrocytes as determined by IFAT ( Figure 1B ; Table 2 ). As seen before for human antibodies, recognition was restricted to blood stages since sporozoites were negative in IFAT assays (data not shown) and by IFAT competition assays with the corresponding peptide ( Figure 1B ). Anti-peptide 27 mouse antibodies, which are positive in IFAT, are also specific for the homologous peptide 27 but not for the sequence related peptides 9, 12 and 45 (Table S2) . Thus, peptides, which were chosen for their propensity to form ahelical coiled coil, can induce the production of antibodies that recognize epitopes present in the native protein. Improvement of the immunogenicity and structural specificity of the remaining peptides might be achieved in the future by a) a short elongation at the N-and C-terminal ends, b) stabilizing the a-helix as suggested by Cooper et al. and Lu and Hodges [17, 18] and/or c) use of other adjuvants.