Fig. 3 |. Reactivity of anti-SARS-CoV-2 RBD monoclonal antibodies.

a, Graph shows anti-SARS-CoV-2 RBD antibody reactivity. ELISA EC₅₀ values for all antibodies measured at 1.3 months¹, and 122 selected monoclonal antibodies measured at 6.2 months. Horizontal bars indicate geometric mean. Statistical significance was determined using two-tailed Mann–Whitney U-test. b, EC₅₀ values for all 52 antibodies that appear at 1.3 and 6.2 months. Average of two or more experiments. Horizontal bars indicate geometric mean. Statistical significance was determined using two-tailed Wilcoxon matched-pairs signed-rank test. c, Surface representation of the RBD with the ACE2-binding footprint indicated as a dotted line and selected residues found in circulating strains (grey) and residues that mediate resistance to class-2 (red) (C144) and −3 (green) (C135) antibodies highlighted as sticks. d, Graphs show ELISA binding curves for C144 (black dashed line) and its clonal relatives obtained after 6.2 months (C050, C051, C052, C053 and C054) (solid lines) binding to wild-type (WT), Q493R, R346S and E484K RBDs. e. Heat map shows log₂-transformed relative fold change in EC₅₀ against indicated RBD mutants for 26 antibody clonal pairs obtained at 1.3 and 6.2 months with the most pronounced changes in reactivity. The participant of origin for each antibody pair is indicated above. All experiments were performed at least twice.