Fc-mediated pan-sarbecovirus protection after alphavirus vector vaccination

Cell Rep. 2023 Apr 25;42(4):112326. doi: 10.1016/j.celrep.2023.112326. Epub 2023 Mar 30.

Abstract

Group 2B β-coronaviruses (sarbecoviruses) have caused regional and global epidemics in modern history. Here, we evaluate the mechanisms of cross-sarbecovirus protective immunity, currently less clear yet important for pan-sarbecovirus vaccine development, using a panel of alphavirus-vectored vaccines covering bat to human strains. While vaccination does not prevent virus replication, it protects against lethal heterologous disease outcomes in both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and clade 2 bat sarbecovirus challenge models. The spike vaccines tested primarily elicit a highly S1-specific homologous neutralizing antibody response with no detectable cross-virus neutralization. Rather, non-neutralizing antibody functions, mechanistically linked to FcgR4 and spike S2, mediate cross-protection in wild-type mice. Protection is lost in FcR knockout mice, further supporting a model for non-neutralizing, protective antibodies. These data highlight the importance of FcR-mediated cross-protective immune responses in universal pan-sarbecovirus vaccine designs.

Keywords: CP: Immunology; FcR effector function; animal model; antibody responses; coronavirus; correlates of protection; cross-protection; pan-coronavirus vaccine; sarbecovirus; systems serology; vaccine development.

Publication types

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

MeSH terms

  • Alphavirus*
  • Animals
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19* / prevention & control
  • Chiroptera*
  • Humans
  • Mice
  • SARS-CoV-2
  • Severe acute respiratory syndrome-related coronavirus*
  • Vaccination
  • Viral Vaccines*

Substances

  • Viral Vaccines
  • Antibodies, Viral
  • Antibodies, Neutralizing