SVA virus-like vesicle vaccine based on VEEV-VSVG vector elicits efficient immune responses and protection in swine

Seneca Valley virus (SVV), a member of the Picornaviridae family，which is closely associated with porcine idiopathic vesicular disease (PIVD), spread quickly and has posed a potential threat to the swine industry in several countries. Currently, SVA demonstrate persistent genetic evolution, yet no licensed vaccines or effective therapeutics are commercially available for disease containment，which underscores the significance of strategies for preventing and controlling SVA infection. A Venezuelan equine encephalitis virus (VEEV) replicon system expressing Vesicular stomatitis virus glycoprotein (VSVG) was constructed in the preliminary research. In this study, we developed a recombinant virus-like vesicles (rVLVs) vaccine expressed SVA VP1 and VP2 protein based on the VEEV-VSVG system and evaluated the characterization and stability. Subsequently, immunization with rVLVs vaccine elicited robust humoral and cellular immune responses in both mice and swine. In addition, the swine challenge experiment manifested that immunization with rVLVs-SVA-VP2 conferred complete protection, comparable to the inactivated vaccine, whereas rVLVs-SVA-VP1 vaccination demonstrated a 60 % protective efficacy.