Fig. 4: RBD–scNP vaccination alone or as a boost can prevent virus replication in the upper and lower respiratory tract after intranasal and intratracheal SARS-CoV-2 challenge in macaques.
From: Neutralizing antibody vaccine for pandemic and pre-emergent coronaviruses
a, Study design for intranasal and intratracheal challenge of macaques with SARS-CoV-2. Blue and burgundy arrows indicate the time points for RBD–scNP and S-2P mRNA-LNP immunizations, respectively. b, Infectious virus in macaque BAL fluid two days after challenge. LOD, limit of detection. c–f, Quantification of viral E gene (c, d) or N gene (e, f) sgRNA in unimmunized (grey) and RBD–scNP-immunized (blue) macaques, and in macaques with a S-2P mRNA-LNP prime and RBD–scNP boost (burgundy). sgRNA in nasal swabs (c, e) and BAL fluid (d, f) was quantified two (left panels) and four (right panels) days after challenge. LOD for the assay is 150 copies per ml. Symbols and bars represent individual macaques and group mean, respectively. g Nucleocapsid immunohistochemistry of lung tissue sections at seven days after challenge. Left, representative image from 1 macaque from each group of 5 macaques is shown. Red arrows indicate site of antigen positivity. All images are shown at 10× magnification. Scale bars, 100 μm. Right, quantification of lung viral antigen positivity. In each panel, symbols represent individual macaques (group mean is shown as a black horizontal bar).
