Synthesis and immunological evaluation of TLR1/2 ligand-conjugated RBDs as self-adjuvanting vaccine candidates against SARS-CoV-2.

We synthesized and evaluated Pam 3 CSK 4 -conjugated receptor binding domain (RBD)/deglycosylated RBD as potential anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine candidates. Our investigation revealed the critical importance of limiting the number of introduced Pam 3 CSK 4 molecules to the RBD in order to preserve its antigenicity. We also confirmed the harmonious integration of the adjuvant-conjugation strategy with the glycan-shield removal strategy.