A Divalent nanoparticle vaccine Confers Robust Protective Immunity against FMDV and SVA in Pigs

Based on our pre-established FMDV/SVA nanoparticle vaccine platform, this study screened and optimized nanoparticle antigens FMDV T3D-LS-LOOP and SVA VP1(B)-β-VP2, developed a bivalent FMDV/SVA nanoparticle vaccine via Escherichia coli prokaryotic expression system, and systematically evaluated its immune protective efficacy and biosafety in pigs.

Results showed that this bivalent vaccine induced high-level neutralizing antibodies and specific IgG responses equivalent to monovalent inactivated vaccines, with strong cross-neutralizing activity against type O FMDV Mya98/Cathay lineages. It triggered Th2-type cellular immune responses against both pathogens, building a dual immune barrier via humoral and cellular immunity synergy. The vaccine showed excellent safety with no notable adverse reactions; challenge tests confirmed it completely inhibited viral replication, dissemination and shedding, reduced tissue viral loads, blocked horizontal transmission, eliminated vesicular lesions, and provided full immune protection against both viruses.