Figure 3.

Efficacy of SS.V1 against lethal MERS-CoV challenge in mice

(A) 288/330^+/+ mice (N = 20/group) were immunized at weeks 0, 3, and 9 with PBS (gray) or 10 μg of MERS-CoV S-2P (red) or SS.V1 (blue) adjuvanted with SAS.

(B–C) At week 11 (two weeks post-boost 2), mice were bled for analysis of MERS-CoV S-2P-specific IgG (B) and MERS-CoV maM35c4 pseudovirus neutralizing antibodies (C).

(D) Following challenge, mice were monitored for weight loss. The mean of each group is represented by a circle, error bars represent SEM.

(E–H) At days 3 and 5 post-challenge, a subset of mouse lungs (n = 5/time point) was harvested for analysis of viral titers (E and F) and tissue discoloration (G and H) (0 = no discoloration, 4 = severe discoloration in all lobes). (B, C, and E–H) Each circle represents an individual mouse. Box and whisker plots are shown. Boxes and horizontal bars denote the interquartile range (IQR) and medians, respectively; whisker end points are equal to the maximum and minimum values. Dotted lines represent lower limit of detection.

In (B) to (C) and (E) to (H)experimental groups were compared to the PBS control group by one-way ANOVA with Kruskal-Wallis post-test. In (D), experimental groups were compared to the PBS control group at each day post challenge by one-way ANOVA with Kruskal-Wallis post test. Statistics account for varability in mouse numbers following lung harvest. ND indicates statistical analysis is not determined due to limited number of PBS control mice. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001, ^∗∗∗∗p < 0.0001.