A Rabies Virus Nucleocapsid-Like Nanostructure Vaccine Based on Dual-Cationic Lipid Nanoparticles

Based on a dual-cationic lipid nanoparticle (LNP) platform, we developed a novel rabies virus (RABV) nucleocapsid-like nanostructure (NLS) vaccine. The antigen comprises two nucleocapsid components: a mRNA encoding the RABV glycoprotein (G-mRNA) and a recombinant RABV nucleoprotein (RABV-N) expressed in Escherichia coli (E. coli). These components are co-encapsulated within dual-cationic LNPs to form the RABV NLS vaccine. Compared with the G-mRNA vaccine and inactivated vaccine (INV), the NLS vaccine elicits significantly stronger humoral and cellular immune responses. Seven days after a single dose, the NLS vaccine elicited neutralizing antibody titers of ~10 IU mL-1. Following two doses on days 0 and 21, the peak neutralizing antibody titer reached 1,000 IU mL-1, and 100% of mice survived a challenge with 25 LD₅₀ of the fixed RABV strain on day 14 post-boost.