Fig. 2. Antibody protection against Omicron variants in K18-hACE2 mice.
a–j Eight-week-old female K18-hACE2 mice received 200 μg (about 10 mg/kg) of the indicated mAb treatment by intraperitoneal injection one day before intranasal inoculation with 103 FFU of the indicated SARS-CoV-2 strain. Tissues were collected at six (BA.2) or seven days (all other strains) after inoculation. Viral RNA levels in the lungs (a, e), nasal turbinates (c, g), and nasal washes (d, h) were determined by RT-qPCR, and infectious virus in the lungs (b, f) was assayed by plaque assay (lines indicate median ± SEM.; n = 6–8 mice per group, two experiments; Two-tailed Mann-Whitney test between isotype and mAb treatment; ns, not significant; *P < 0.05, **P < 0.01, ***P < 0.001). i, j Heat map of cytokine and chemokine protein expression levels in lung homogenates from the indicated groups. Data are presented as log2-transformed fold-change over naive mice. Blue, reduction; red, increase. k, l, Correlation analysis. The fold-change in EC50 value of AZD7442-YTE/TM (k) and S309-LS (l) for D614G and each Omicron variant strain are plotted on the x-axis. The fold-change in lung viral RNA titer between the respective isotype or mAb-treated groups against each Omicron variant strain are plotted on the y-axis. Best-fit lines were calculated using a simple linear regression. Two-tailed Pearson correlation was used to calculate the R2 and P values indicated within each panel. Source data are provided as a Source Data file.