FIG 6.

Induction of specific antibody responses in mice immunized with recombinant adenoviruses expressing P. vivax CSP as part of a heterologous prime-boost regimen of vaccination. (A and B) Schematic representations and deduced amino acid (aa) sequences of the PvCSP-All-CSP-epitopes expressed by recombinant replication-defective simian or human adenovirus. (C) C57BL/6 mice were immunized i.m. at 2 × 10⁷ PFU/mouse with AdHu5-βgal (control), AdC68-PvCSP, or AdHu5-PvCSP. Serum titers of IgG against recombinant proteins of each allelic form of PvCSP were determined 21 days later as indicated. Mice immunized with AdC68-PvCS and AdHu5-PvCS responded equally well according to statistical comparisons (one-way ANOVA, no statistically significant difference [NS]). The results are expressed as means ± SD (n = 5). (D) Mice were boosted s.c. 42 days after being primed with a formulation containing a protein mixture (His₆-PvCSP-VK210, His₆-PvCSP-VK247, and His₆-PvCSP-Vivax-like, 3 μg/dose/mouse) in the presence of poly(I·C). The titers of specific antibodies to the different allelic forms of PvCSP were measured at day 63. According to statistical comparisons (one-way ANOVA, Tukey's HSD test), mice immunized with AdC68-PvCS and AdHu5-PvCS and boosted with a protein mixture (G5 and G6) had serum IgG antibody titers higher than those of the other groups, as shown.