Convergent antibody responses to the SARS-CoV-2 spike protein in convalescent and vaccinated individuals

Unrelated individuals can produce genetically similar clones of antibodies, known as public clonotypes, which have been seen in responses to different infectious diseases, as well as healthy individuals. Here we identify 37 public clonotypes in memory B cells from convalescent survivors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or in plasmablasts from an individual after vaccination with mRNA-encoded spike protein. We identify 29 public clonotypes, including clones recognizing the receptor-binding domain (RBD) in the spike protein S1 subunit (including a neutralizing, angiotensin-converting enzyme 2 [ACE2]-blocking clone that protects in vivo) and others recognizing non-RBD epitopes that bind the S2 domain. Germline-revertant forms of some public clonotypes bind efficiently to spike protein, suggesting these common germline-encoded antibodies are preconfigured for avid recognition. Identification of large numbers of public clonotypes provides insight into the molecular basis of efficacy of SARS-CoV-2 vaccines and sheds light on the immune pressures driving the selection of common viral escape mutants. [Display omitted] •Public clonotypes are shared among SARS-CoV-2-vaccinated and -infected individuals•Group 3 antibodies share the same binding site as CR3022 but neutralize variants•Germline-revertant forms of public clonotypes bind efficiently to spike protein•Public clonotype responses inform research on new viral variants of concern Chen et al. describe neutralizing and non-neutralizing public antibodies elicited to SARS-CoV-2 spike in vaccinated and naturally infected individuals. Germline-revertant forms of some public clonotypes bind efficiently to spike protein, suggesting common germline-encoded properties for recognition.