Clinical observations. (a) Schematic of experimental design. Ferrets received INNA-051 and PBS treatments 4 days and 1 day prior to challenge with 5.0 × 106 pfu/ml SARS-CoV-2. Nasal wash and throat swabs were collected at days 1, 3, 5, 7, 10 & 12 post challenge (p.c.) for all treatment groups and control group. Scheduled culls were performed for 6/24 ferrets on day 3 p.c. (group 1 n=2, group 2 n=2, group 4 n=2) and 18/24 ferrets on days 12-14 p.c. (b) Temperatures were measured twice daily (approximately 8 hours apart), using implanted temperature/ID chips. Mean temperatures +/- standard error of the mean (SEM) are displayed. Temperature dip post SARS-CoV-2 challenge (*) was attributed to sedation. Group 1 animals were first to come out of sedation and therefore recover temperatures. (b) Weight was recorded daily and percentage change from the ferret weight prior to treatment plotted. Mean percentage weight change +/- SEM are displayed. Weight dips on days 4 and 8 p.c. (*) attributed to 2/4 ferrets in group 2 losing weight due to thirst after upturning water bowl overnight. Ferrets in group 3 (2/6 animals) lost weight for same reason on day 8 p.c.