Figure 5.

DENV-2 strains carrying the late epidemic NS5_357E variant exhibited higher virulence in AGB6 mice

(A) AGB6 mice were infected with 500 PFU of the infectious clone-derived viruses (n = 5 for each group) by footpad injection. To assess the virulence of infectious clone-derived viruses, their impact on AGB6 mice was evaluated through survival (B) and viral load measurements in serum collected at 4 d.p.i. (C) and 6 d.p.i. (D). Virus titers are represented as mean ± SD. Survival analysis was performed with Kaplan-Meier curves to compare the survival difference between each group and the Ia-inoculated group according to survival rate and medium survival time (T₅₀). Significance was indicated as ∗p < 0.05, ∗∗p < 0.01. Statistical analysis for differences in virus titers in mouse serum between Ia and the mutant viruses was conducted using one-way ANOVA, with significance indicated as ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.