Fig. 4: Virus titration and quantitation in the lower respiratory tract of animal models.

Three ferrets per group were euthanized at 3 and 7 dpi, and lungs were collected to measure viral titers (a) and the number of viral RNA copies (d). Golden Syrian hamsters (n = 12/group) were challenged intranasally with 6.4 × 10⁴ PFU/80 μL of SARS-CoV-2. Vehicle and 15, 30, 60, and 90 mg/kg of CT-P59 were intraperitoneally administered 24 h after virus inoculation. Four animals were euthanized for virus titration (b) and quantitation of viral RNA copies (e) from each group at 3 and 5 dpi. Rhesus monkeys (control n = 3, 45 mg/kg n = 2, 90 mg/kg n = 3) were infected with 10^6.4 TCID₅₀/ml of SARS-CoV-2 via in a combination of intranasal (0.5 ml), intratracheal (4 ml), ocular (0.25 ml/eye), and oral (1 ml) routes. Vehicle, 45 mg/kg and 90 mg/kg of CT-P59 were administered intravenously after 24 h of virus infection. All rhesus monkeys were euthanized at 6 dpi, and lungs were collected to measure viral titers (c) and the number of viral RNA copies (f). Viral titers in the lung were determined by TCID₅₀ assessment in Vero cells and viral RNA copy number measurement using qRT-PCR. Viral titers and RNA copy numbers are shown as mean value + /− SEM and titers below the limit of detection are shown as 0.8 log₁₀TCID₅₀/ml or 0.3 log₁₀ viral RNA copies/ml (dashed lines). Asterisks indicate statistical significance between the control and each group as determined by two-way ANOVA and subsequent Dunnett’s test. *P = 0.0309, **P = 0.0131, and ***P < 0.0001 (a); *P = 0.0002 and **P < 0.0001 (b); *P = 0.0329 (d); and *P = 0.0123, **P = 0.0025, ***P = 0.0003, and ****P = 0.0002 (e).