Fig. 4: Epitope distribution and characterization of monoclonal antibodies elicited by Omicron BTI and reinfection.

a, UMAP embedding of epitope groups of monoclonal antibodies binding BA.5 RBD isolated from convalescent individuals who experienced BA.5/BF.7 BTI or reinfection (n = 1,350). b, Neutralization activities, denoted as IC₅₀ values, for SARS-CoV-2 D614G (n = 1,349), BA.4/5 (n = 1,322) and XBB.1.5 (n = 1,346) spike-pseudotyped VSV, and ACE2 competition determined by ELISA (n = 1,344), are projected onto the UMAP embedding space. c, Distribution of monoclonal antibodies across epitope groups is shown for BA.5 BTI, BF.7 BTI, BA.1 BTI with BA.5/BF.7 reinfection and BA.2 BTI with BA.5/BF.7 reinfection. Epitope groups predominantly comprising non-neutralizing or weakly neutralizing monoclonal antibodies (E2.2, E3 and F1) are highlighted with dashed boxes. The percentage of antibodies in these three groups is labelled on each bar. d, Average DMS escape scores of the crucial epitope groups contributing to neutralization against XBB.1.5 are indicated on the structure model of the SARS-CoV-2 BA.5 RBD (PDB: 7XNS). Key residues with high escape scores for each group are labelled. e, The average DMS escape scores for the key epitope groups are represented as sequence logos; residues are depicted using the standard one-letter code and coloured on the basis of their chemical properties. The height of each letter corresponds to the escape score of the respective mutation. f, Pseudovirus-neutralization activities of monoclonal antibodies in the six crucial epitope groups (A1 (n = 170), A2 (n = 60), B (n = 33), F3 (n = 129), D3 (n = 155) and D4 (n = 80); n refers to the number of monoclonal antibodies) are shown against SARS-CoV-2 D614G, BA.5, BQ.1.1 and XBB.1.5. Geometric mean IC₅₀ values are displayed as bars and indicated above each group of data points.