Figure 1.
The P.1 variant induced a greater weight loss and clinical manifestation than the Delta variant and Wt strain in ACE2-transgenic mice. (A,B) The average of weight loss of K18-hACE2 transgenic mice infected intranasally with 105 PFU of the Wt strain and the P.1 and Delta variants. The P.1-infected mice were euthanized on the 5th dpi, and the Wt- and Delta-infected mice on the 7th dpi. Analysis of body weight (B) on the 5th dpi showed significant differences between the P.1 variant and the control. The clinical manifestations of the disease in K18-hACE2 mice were more pronounced in the group infected with the P.1 variant when compared to the Delta variant or the Wt strain (C). The probability of survival was reduced when the mice were infected with the P.1 variant compared to Delta or Wt strain (D). The hypothesis test performed by a one-way ANOVA, with Bonferroni multivariance analysis for the parametric variables, or Brown–Forsythe and Welch ANOVA tests with the Games–Howell multiple comparisons test for values with asymmetric distribution, the survival Log-rank (Mantel–Cox) test was applied, using GraphPad Prism 8.0, p < 0.05 was considered significant (* p ≤ 0.05; ** p ≤ 0.005; **** p ≤ 0.0001).