Rational optimization of glycoprotein E (gE)-encoding mRNA for improved Varicella-zoster virus mRNA vaccine development.

mRNA platform holds promise for next-generation Varicella-zoster Virus (VZV) vaccine development due to its high potency at inducing strong T-cell response. Built upon the design of our 1st-generation VZV mRNA vaccine that encodes for full-length gE antigen, in this study we reported on a novel combinatorial strategy to further optimize the gE-encoding mRNA sequence through signal peptide replacement, C-terminal modification, and insertion of mRNA-stabilizing motif, which collectively contributed to significantly improved vaccine immunogenicity. In adult mice, aged mice, and immunocompromised mice, this optimized VZV mRNA vaccine showed strong superiority in multiple aspects including the induction of gE-specific antibodies, specific memory B-cell response, as well as Th1-type T-cell response.