Figure 3.

SARS-CoV-2 mRNA antigen immunogenicity and vaccine design. Full-length S-protein or RBD as a vaccine immunogen has been widely confirmed to induce high-affinity neutralizing antibodies. The SARS-CoV-2 S protein is intrinsically metastable and can be stabilized in a prefusion conformation by structure-based design. Prefusion-stabilized SARS-CoV-2 spike immunogen induces potent humoral and cellular immune responses. The RBD peptide is one of the most promising targets to design candidate vaccines. However, RBD has a low molecular weight, which leads to its weak immunogenicity, and can be further improved by forming multimers. Multimerization of RBD protein using humanized IgG Fc, T4 trimerization (FD), or ferritin has been shown to induce higher neutralizing antibodies compared to monomeric antigens, which will provide us with new ideas for designing powerful mRNA vaccines. (Adopted under Creative Commons Attribution 4.0 International License from [7]).