Fig. 6: HexaPro-SS provides partial protection against SARS-CoV challenge.

After being immunized with respective S antigens or PBS, BALB/cAnNHsd mice were challenged with a lethal dose of mouse-adapted SARS-CoV (n = 14 mice for HexaPro and PBS PBS, n = 15 mice for all other groups). a Mouse body weights were monitored daily following challenge, and the percentage of body weight loss over time is represented by a line plot summarized per strain per day by the mean ± SD. We analyzed the change in body weight using mixed models with repeated measures (exact P values for each term and the interaction is reported in the plot) followed by Tukey post-tests (n = 14 mice for HexaPro and PBS PBS, n = 15 mice for all other groups at day 0). One animal from the HexaPro-immunized group as well as one animal from the HexaPro-SS-immunized group reached 70% of their starting weight on day 7 after infection. Per-day comparisons with post-tests <0.05 are indicated with symbols defined in the key. b, The survival graph represents the probability of survival over two to seven days post-challenge (n = 5 mice per group). The Mantel-Cox log-rank test determined the survival curves were different (χ² = 25.36, df = 6, P = 3e-4) and the two-stage linear step-up procedure of Benjamini, Krieger and Yekutieli identified the pairwise differences of survival curves with a false discovery rate (Q) < 5%. c The congestion score in lung and the viral titers in d, nasal turbinate and e, lung (N per group listed in the graphs) are represented by dot plot, summarized by the median ± IQR. We analyzed the congestion scores and titers using ANOVA on ranks per day with each P value reported in the figure. Dunn’s pairwise comparison post-tests for p < 0.05 and p < 0.01 are noted by * and ***, respectively. Source data are provided as a Source Data file.