Fig. 2: Protective efficacy of the ΔEM vaccine candidate virus in K18-hACE2 mice.
From: SARS-CoV-2 virus lacking the envelope and membrane open-reading frames as a vaccine platform
a, b Body weight changes (a) and survival rate (b) (n = 12 females in each vaccinated group, n = 8 females in the control group) of hACE2 mice vaccinated once or twice with the ΔEM virus and then challenged with an ancestral SARS-CoV-2 isolate. Data represent the mean, and error bars indicate SD (a). Statistical significance was determined by use of the two-tailed Dunnett’s multiple comparisons test (a; *P < 0.05, **P < 0.01, ****P < 0.0001) and the Log-rank Mantel-Cox test (b; *P = 0.033). Exact P values: (a) control vs. ΔEM x2: day 4 (P = 0.0360), day 5 (P = 0.0012), day 6 (P < 0.0001), day 7 (P < 0.0001), day 8 (P = 0.0022), day 9 (P = 0.0348); control vs. ΔEM x1: day 5 (P = 0.0020), day 6 (P < 0.0001), day 7 (P = 0.0001), day 8 (P = 0.0064). c Efficacy of one or two vaccinations of the ΔEM vaccine candidate virus. Virus titers in the lung and nasal turbinate (NT) tissues of K18-hACE2 mice (mean with SD, n = 8 females/group) at 3 days after challenge with an ancestral SARS-CoV-2 isolate. The dotted line indicates the limit of detection (1.3 log10 pfu/g). Each dot in the bar graph indicates an individual mouse in each group. Statistical significance was determined by use of a one-way ANOVA with Dunnett’s multiple comparisons test (****P < 0.0001). Source data are provided as a Source Data file.
