Fig. 1.

Cell entry sensitivity test with pseudotyped SARS-CoV, SARS-CoV-2 and MERS-CoV viruses. (a) Huh7.5 cells are sensitive to infection with ppSARS, ppSARS-2 and ppMERS, with similar entry levels between ppSARS and ppSARS-2 (p > 0.1, two-way ANOVA). (b) HEK 293T cells were transiently transfected with the hACE2 expression plasmid. ppSARS and ppSARS-2 were both found to significantly enhance the infection ratio (p < 0.001, two-way ANOVA). Similar levels of entry were observed in hACE2 transfected 293T cells (p > 0.1, two-way ANOVA). (c) VeroE6 cells were infected with live SARS-CoV-2 in the presence of soluble ACE2 at different concentrations, in which 30 µg/mL of soluble ACE2 was found to inhibit virus replication. **P < 0.01, ****P < 0.0001.