Figure 1.

repRNA vaccination elicits humoral and cellular immunity to CCHFV. WT C57BL6/J mice were given (a) prime boost vaccinations at days -56 and -28 relative to CCHFV challenge on day 0. On day 0 groups of four mice vaccinated with 2.5μg (sham, repNP, repGPC) or 5μg (repNP + repGPC) of RNA were evaluated for immune responses to CCHFV. CCHFV-specific antibody was measured by whole-virion ELISA for total IgG (b) or specific isotypes (c). Dashed line indicates background absorbance of wells that received no serum. Serum neutralization activity was measured by a microneutralization assay against infectious CCHFV strain Hoti (d). Dashed line indicates limit of detection and statistical significance calculated using a one-way ANOVA with Dunnett's multiple comparison test. CCHFV-specific T-cell responses were measured by IFNγ ELISpot (e – g). Cumulative SFCs against peptide pools spanning the entire NP or GPC, the mitogen concanavalin a (CA) or DMSO vehicle alone (veh) are shown. Statistical comparisons calculated using a two-way ANOVA with Dunnett's multiple comparison test (c – e) Heat maps showing the distribution of measured IFNγ SFCs against NP (e) or GPC (f) peptide pools. ns P > 0.05, *** P < 0.001. (b – e) Data shown as mean plus standard deviation.