FIG 4.
The s2m is dispensable for SARS-CoV-2 viral fitness in Syrian hamster. The fitness of the CoV-2-s2mΔ2–42 virus was assessed in vivo in Syrian hamsters. Hamsters were inoculated intranasally with a 1:1 mixture of CoV-2-s2m-WT and CoV-2-s2mΔ2–42 viruses, and lungs and nasal washes were collected 3 days postinfection. The genome copy of CoV-2-s2m-WT and CoV-2-s2mΔ2–42 in the inoculum and infected tissues were measured by RT-PCR. (A) The ratio of CoV-2-s2m-WT to CoV-2-s2mΔ2–42 in the inoculum was calculated. (B) The replicative fitness of the CoV-2-s2mΔ2–42 to CoV-2-s2m-WT virus in lungs and nasal washes was calculated. Individual values were shown as dots, and mean values were plotted by box.