Reduced neutralization of SARS-CoV-2 B.1.617 by vaccine and convalescent serum

Cell. 2021 Aug 5;184(16):4220-4236.e13. doi: 10.1016/j.cell.2021.06.020. Epub 2021 Jun 17.

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has undergone progressive change, with variants conferring advantage rapidly becoming dominant lineages, e.g., B.1.617. With apparent increased transmissibility, variant B.1.617.2 has contributed to the current wave of infection ravaging the Indian subcontinent and has been designated a variant of concern in the United Kingdom. Here we study the ability of monoclonal antibodies and convalescent and vaccine sera to neutralize B.1.617.1 and B.1.617.2, complement this with structural analyses of Fab/receptor binding domain (RBD) complexes, and map the antigenic space of current variants. Neutralization of both viruses is reduced compared with ancestral Wuhan-related strains, but there is no evidence of widespread antibody escape as seen with B.1.351. However, B.1.351 and P.1 sera showed markedly more reduction in neutralization of B.1.617.2, suggesting that individuals infected previously by these variants may be more susceptible to reinfection by B.1.617.2. This observation provides important new insights for immunization policy with future variant vaccines in non-immune populations.

Keywords: B.1.617; Delta variant; Receptor-binding-domain; SARS-CoV-2; antibody; escape; neutralization; structure; vaccine; variant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology
  • Antibodies, Neutralizing / immunology
  • Antibodies, Viral / immunology*
  • Antigen-Antibody Complex / chemistry
  • COVID-19 / pathology
  • COVID-19 / therapy
  • COVID-19 / virology
  • COVID-19 Serotherapy
  • COVID-19 Vaccines / administration & dosage
  • COVID-19 Vaccines / immunology*
  • Chlorocebus aethiops
  • Crystallography, X-Ray
  • Humans
  • Immunization, Passive
  • Neutralization Tests
  • Protein Domains / immunology
  • SARS-CoV-2 / genetics
  • SARS-CoV-2 / immunology*
  • SARS-CoV-2 / isolation & purification
  • Spike Glycoprotein, Coronavirus / chemistry
  • Spike Glycoprotein, Coronavirus / immunology
  • Vero Cells

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Antigen-Antibody Complex
  • COVID-19 Vaccines
  • Spike Glycoprotein, Coronavirus
  • spike protein, SARS-CoV-2