Sequential immunization with SARS-CoV-2 RBD vaccine induces potent and broad neutralization against variants in mice

Virol J. 2022 Jan 4;19(1):2. doi: 10.1186/s12985-021-01737-3.

Abstract

The current COVID-19 pandemic caused by constantly emerging SARS-CoV-2 variants still poses a threat to public health worldwide. Effective next-generation vaccines and optimized booster vaccination strategies are urgently needed. Here, we sequentially immunized mice with a SARS-CoV-2 wild-type inactivated vaccine and a heterologous mutant RBD vaccine, and then evaluated their neutralizing antibody responses against variants including Beta, Delta, Alpha, Iota, Kappa, and A.23.1. These data showed that a third booster dose of heterologous RBD vaccine especially after two doses of inactivated vaccines significantly enhanced the GMTs of nAbs against all SARS-CoV-2 variants we tested. In addition, the WT and variants all displayed good cross-immunogenicity and might be applied in the design of booster vaccines to induce broadly neutralizing antibodies.

Keywords: Broadly neutralizing antibody; Inactivated vaccine; Mutant RBD vaccine; SARS-CoV-2 variant; Sequential immunization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neutralizing / immunology
  • Antibodies, Viral / immunology
  • COVID-19 Vaccines* / administration & dosage
  • COVID-19 Vaccines* / immunology
  • COVID-19* / immunology
  • COVID-19* / prevention & control
  • Mice
  • SARS-CoV-2* / immunology

Substances

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

Supplementary concepts

  • SARS-CoV-2 variants