Infection- and vaccine-induced antibody binding and neutralization of the B.1.351 SARS-CoV-2 variant

Cell Host Microbe. 2021 Apr 14;29(4):516-521.e3. doi: 10.1016/j.chom.2021.03.009. Epub 2021 Mar 20.


The emergence of SARS-CoV-2 variants with mutations in the spike protein is raising concerns about the efficacy of infection- or vaccine-induced antibodies. We compared antibody binding and live virus neutralization of sera from naturally infected and Moderna-vaccinated individuals against two SARS-CoV-2 variants: B.1 containing the spike mutation D614G and the emerging B.1.351 variant containing additional spike mutations and deletions. Sera from acutely infected and convalescent COVID-19 patients exhibited a 3-fold reduction in binding antibody titers to the B.1.351 variant receptor-binding domain of the spike protein and a 3.5-fold reduction in neutralizing antibody titers against SARS-CoV-2 B.1.351 variant compared to the B.1 variant. Similar results were seen with sera from Moderna-vaccinated individuals. Despite reduced antibody titers against the B.1.351 variant, sera from infected and vaccinated individuals containing polyclonal antibodies to the spike protein could still neutralize SARS-CoV-2 B.1.351, suggesting that protective humoral immunity may be retained against this variant.

Keywords: SARS-CoV-2; emerging variants; humoral immunity; receptor-binding domain; vaccine; viral neutralization.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Neutralizing / immunology*
  • Antibodies, Viral / immunology*
  • Binding Sites
  • COVID-19 / immunology*
  • COVID-19 / prevention & control
  • COVID-19 Vaccines / immunology*
  • Humans
  • Neutralization Tests
  • Receptors, Virus / chemistry
  • SARS-CoV-2 / immunology*


  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19 Vaccines
  • Receptors, Virus

Supplementary concepts

  • SARS-CoV-2 variants