Fig. 6
NVRBD-MLipo inhibited the infection of SARS-CoV-2 pseudovirus. (A) Timeline of in vivo vaccination and challenge. Mice were immunized with different groups via inhalation (nebulization, N) or subcutaneous (Sc) injection on days 0, 7, and 14, and further challenged intranasally with SARS-CoV-2 WT pseudovirus. (B) The in vivo fluorescence imaging of immunized mice at different time points post challenge (n = 3). Ex vivo fluorescence (C) and immunofluorescence (D) imaging of lungs at day 6 after challenge (n = 3). Serum (E) and BALF (F) neutralizing capacity against SARS-CoV-2 WT, Delta, Omicron pseudovirus (n = 3). The serum and BALF were collected from immunized mice on day 28. Data expressed as means ± SD. *p < 0.05; **p < 0.01