Fig. 2: Differences in virus replication kinetics in hamsters inoculated with Omicron variants.

Hamsters were inoculated intranasally with 10⁴ TCID₅₀ of indicated Omicron variants (N = 4 per variant). A Viral loads in oropharyngeal swabs were determined (sgRNA = SARS-CoV-2 subgenomic RNA). The dashed line indicates lower limit of quantification = 3.5 log₁₀ copies per mL. B Area under the curve (AUC) analysis of viral shedding as measured by sgRNA in oropharyngeal swabs from (A). Error bars denote mean +/− SD. C, D Virus replication in lungs and nasal turbinates of hamsters at 5 DPI. Viral loads (C) and virus titers (D) were determined. The dashed line indicates the lower limit of quantification = 3.5 log₁₀ copies per mL and the limit of detection = 0.5 log₁₀ TCID₅₀ per gram, respectively. Error bars denote the median with the interquartile range. E Lung/body weight ratio of hamsters at the time of euthanasia. Healthy, age-matched hamsters were used as controls. Error bars denote mean +/− SD. F Semi-quantitative scores were assigned to histopathological changes in the lungs of hamsters by a board-certified veterinary anatomic pathologist, as was the amount of virus antigen immunohistochemistry (IHC). Error bars denote mean +/− SD. Statistical analysis was conducted using two-way ANOVA followed by Tukey’s post-test (A, C, D) or Kruskall-Wallis test followed by Dunn’s multiple comparisons correction (B, E, F). P-values adjusted for multiple comparisons < 0.05 are shown.