Figure 2
Immunogenicity and efficacy of RTS,S/AS01 and PbTRAP based viral-vector combinations. C57BL/6 mice were immunized with RTS,S/AS01 and/or ChAd63 PbTRAP—MVA PbTRAP either alone, co-administered or mixed as indicated in Table 3. Two weeks after the final immunization (A) NANP-specific IgG responses and (B) TRAP-specific IgG responses were measured by ELISA. Lines indicate the mean and groups compared by One-way ANOVA with Dunnett’s multiple comparison post-test comparing all pairs of groups. T cell responses were measured in the blood ~ 2 weeks after the final immunization by ICS for (C) CSP-specific cytokine secreting CD4 + T cells or (D) TRAP-specific cytokine secreting CD8 + T cells. Lines indicate the median. Dotted lines indicate average background response. Groups compared by Kruskal–Wallis test with Dunn’s multiple comparison post-test comparing all pairs of groups. Two weeks after the final immunization all immunized mice and 10 naïve mice were challenged with 1000 transgenic P. berghei parasites expressing P. falciparum CSP. Blood-stage parasitemia was monitored from day 5 after challenge by thin-film blood smear, and (E) time to 1% parasitemia was calculated using linear regression. Lines indicate the median and groups compared by Kruskal–Wallis test with Dunn’s multiple comparison post-test comparing all pairs of groups. The results are presented in Kaplan–Meier survival graphs and survival curves compared by Log-rank (Mantel–Cox) Test for (F) individual vaccinations, (G) combination and mixture vaccination, and (H) comparison of individual vaccination to all combinations. R = RTS,S/AS01, A = ChAd63 ME.TRAP, M = MVA ME.TRAP. *P < 0.05, **p < 0.01 and ***p < 0.0001.
