Fig. 3. mRNA-HB27-LNP prevents SARS-CoV-2 transmission in hamsters.

a Experimental design. Briefly, groups of 6–8-week-old female Syrian golden hamsters were i.v. injected with 0.3 or 1 mg/kg of mRNA-HB27-LNP (n = 2 per group) or placebo (n = 4). 24 h later, each of treatment hamster were transferred to a new cage and were cohoused with one index hamster in a one-to-one manner. The index hamsters (n = 8) were infected with 1 × 10⁴ PFU of SARS-CoV-2 through the intranasal route at 1 h prior to cohouse. The lung tissues of hamster were collected at 4 dpi for following-up viral burden determination (by RT-qPCR) and histopathological analysis. b Viral sgRNA loads in lung tissues of hamsters at 4 dpi were determined by RT-qPCR. The dotted line in panel shows the limit of detection of the assay. c Histopathological analysis of each group of lung tissues at 5 dpi. Representative images from 16 hamsters are shown. Scale bar, 200 µm.