Figure 4.
The monovalent and the STFK/STFK1628x-combined bivalent vaccines offer protection against SARS-CoV-2 Omicron variant intranasally challenged in hamsters
(A–E) A total of 40 hamsters were used for challenge. Each group included eight hamsters (4 males and 4 females) that received 2-dose vaccinations (10 μg/dose, 3-week apart) before virus challenges. Hamsters were intranasally challenged with 1 × 105 PFU of SARS-CoV-2 Omicron BA.1. After a 5-day weight monitoring follow-up, animals were euthanized for tissue analyses. Weight changes (A), survival curves (B), lung viral RNA levels (in two independent lung tissues, LOD = 2 log10 copies/mL) (C), and pulmonary pathological scores (D) of challenged hamsters were shown.
(E) Representative gross observations and H&E-stained lung sections from SARS-CoV-2 Omicron BA.1 challenged hamsters. Views of the whole lung lobes (four independent sections) and the gross observations of lung tissues were presented in the top panel (scale bars, 2 mm), areas in the black box were enlarged in the bottom panel (scale bars, 200 μm). Data in (A) were plotted as means ± SEM. Data in (C) and (D) were shown as box and whisker plots. Dunnett's multiple comparison test (A), or uncorrected Kruskal-Wallis test (C and D) were used for intergroup statistical comparisons. Asterisks indicate statistical significance (∗∗∗∗p < 0.0001; ∗∗∗p < 0.001; ∗∗p < 0.01; ∗p < 0.05; ns, not significant).
See also Figure S4.