Clin Exp Vaccine Res.  2022 Sep;11(3):285-289. 10.7774/cevr.2022.11.3.285.

Recombinant proteins of spike protein of SARS-CoV-2 with the Omicron receptor-binding domain induce production of highly Omicron-specific neutralizing antibodies

• Kang H
• Kim D
• Min K
• Park M
• Kim SH
• Sohn EJ
• Choi BH
• Hwang I

• KMID: 2534917
• DOI: http://doi.org/10.7774/cevr.2022.11.3.285

Abstract

Various vaccines have been developed to fight severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease 2019 pandemic. However, new variants of SARS-CoV-2 undermine the effort to fight SARS-CoV-2. Here, we produced S proteins harboring the receptor-binding domain (RBD) of the Omicron variant in plants. Plant-produced S proteins together with adjuvant CIA09A triggered strong immune responses in mice. Antibodies in serum inhibited interaction of recombinant human angiotensinconverting enzyme 2 with RBD of the Omicron variant, but not RBD of other variants. These results suggest that antibodies induced by RBD of the Omicron variant are highly specific for the Omicron RBD, but not for that of other variants.

Keyword

SARS-CoV-2; Vaccine; Omicron variant; Nicotiana benthamiana; Recombinant S protein