Fig. 6: Efficacy of iB12, iB14, and iB6 + iB20 cocktail in treatment and prophylaxis of SARS-CoV-2 infection in a hamster model.

In a prophylactic regimen, antibodies were administered i/p 1 day before infection at a dose of 1 or 0.1 mg/animal (i.e., ~10 or 1 mg/kg weight). Control animals received 1 mg of total human IgG. In the therapeutic regimen, iB12 antibody (1 mg/animal) was given 6 h following the viral challenge (Experiment 1), whereas iB14 antibody was injected either 6 h (0.1 or 1 mg/animal) or 24 h (1 mg/animal) following the viral challenge (Experiment 2). Intact animals formed a separate control group. Animals were sacrificed on day 5 following infection. Lungs were weighted and used for RT-qPCR quantification of the viral load. a Relative weight dynamics in the prophylaxis and treatment groups following administration of iB nAbs or control total human IgG. Error bars represent means ± SD. b Impact of iB nAbs on the levels of viral transcripts in hamster lungs (RT-qPCR with RdRp primers). RT-qPCR with E gene-specific primers produced very similar results (not shown). Animals with strongly reduced human nAb titers in the blood were considered as outliers due to the technical error of nAb injection and were excluded from the analysis. Error bars represent means ± SEM. c Lung pathology scores for hamster lungs at 5 dpi (Supplementary Fig. S9).