Fig. 6: Replication of BA.5 in nasal cavity and lungs.

A Experimental timeline of mouse infection study with Omicron variants. B Percent of initial weight of mice infected with 10⁵ PFU of the indicated variant. Infected mice were monitored and weighed daily for up to day 7 post infection. The dotted line indicates 100% of weight. The average of five animals per time point is shown, error bars indicate SEM. C Infectious virus titers in the lungs of mice infected with 10⁵ PFU Omicron variants, as described for B, were determined by plaque assay in Vero-hACE2-TMPRSS2 cells. Geometric mean viral titers for three to five mice are shown, error bars indicate geometric mean standard deviation. D N gene transcripts levels in the lungs of mice infected with 10⁵ PFU Omicron variants were determined at the indicated time point by quantitative PCR. Presented are the geometric mean transcript levels for three to five animals (each sample was measured in technical duplicates), error bars indicate geometric mean standard deviation. E Levels of selected cytokines/chemokines in the lungs of mice infected with 10⁵ PFU Omicron variants were determined at the indicated time point by quantitative PCR. Presented is the geometric mean transcript abundance for three to five animals (each sample was measured in technical duplicates), error bars indicate geometric mean standard deviation. In C–E, four animals (BA.1 group), five animals (BA.4 group) and three animals (BA.5 group) were analyzed at 2 days post infection while groups of four animals each were analyzed at 5 days post infection. Statistical significance for C–E was determined by two-tailed Student’s t-test (p > 0.05, not significant [ns]; p ≤ 0.05, *; p ≤ 0.01, **; p ≤ 0.001, ***), see also Extended Data Table 6. F Timeline of the ferret infection study with SARS-CoV-2 Omicron BA.5. G Nasal washings of BA.5-inoculated ferrets. Nasal washings were performed for 4 consecutive days and subsequently every 2 days until 8 dpi. Viral genome copies were measured by including a standard of a known SARS-CoV-2 RNA concentration. H Serological analysis of individual ferret sera from 21 dpi via a SARS-CoV-2 Wuhan-strain-based RBD-ELISA. Values > 0.3 = positive and <0.3 = negative.