Fig. 5: Efficacy of P5A-3C8 prophylaxis against live SARS-CoV-2 infection in Syrian hamsters.

a The hamsters were given a single intraperitoneal dose of 5 mg/kg of P5A-3C8 (n = 3), or VRC01, an anti-HIV-1 antibody as negative control (n = 3). On day 4 after viral challenge, the genomic viral RNA in the lung and nasal turbinate tissues were determined by qRT-PCR normalized by beta-actin. The differences between P5A-3C8 group and VRC01 group in lung tissues are statistically significant with two-tailed p value = 0.0064 (**p < 0.01, unpaired t test). b Subgenomic viral RNA in the lung and nasal turbinate tissues on day 4 after viral challenge were determined by qRT-PCR normalized by beta-actin (n = 3). c Infectious virions were tested by viral plaque assay in lung and nasal turbinate tissues. PFUs per mg of tissue extractions were compared between two groups (n = 3). d The body weights of hamsters were monitored over a 4-day time course (n = 3). All data from a–d are shown in mean value ± SD. e Representative images of hamster lung tissues detected for viral NP antigen by immunofluorescence. In the VRC01 group, diffuse NP expression was shown in large areas of alveoli. Sporadic NP expression were observed in lung sections of hamster treated with P5A-3C8. All images were magnified ×200. Scale bar: 50 μm. Results presented in e are representatives of two independent experiments. Source data (a–d) are provided as a Source Data file.