Figure 5.

Protection efficacy of a single-dose regimen of HAd-Spike and HAd-Spike/C5 in golden Syrian hamsters

Six- to seven-week-old golden Syrian hamsters were inoculated i.n. once with 2 × 10⁸ PFUs/animal of HAd-ΔE1E3, HAd-Spike, or HAd-Spike/C5. (A) Four weeks post immunization, blood samples were collected and used to study the development of VN titers against SARS-CoV-2 by VN assay. (B) 35 days post immunization, animal groups were challenged with a 10⁵ tissue culture infectious dose 50 (TCID₅₀) of SARS-CoV-2 (B.1.1.28). Animals were weighed daily for 14 days to monitor morbidity following the challenge. The weight loss or gain percentage with time is shown as a parameter of morbidity. (C–F) Decreases in virus titers in immunized groups following the challenge are shown. Following the challenge, virus titers were determined in the nasal turbinate on days 3 (C) and 5 (D) and in the lungs on days 3 (E) and 5 (F) by TCID₅₀ assay. The titers are shown as log 10 TCID₅₀/g tissue. ns, p > 0.05; ∗p ≤ 0.05; ∗∗p ≤ 0.01; ∗∗∗p ≤ 0.001; ∗∗∗∗p ≤ 0.0001. DPI, days post infection.