Immunogenicity and protective efficacy of an inactivated cell culture-derived Seneca Valley virus vaccine in pigs

Abstract

Seneca Valley virus (SVV) infection in pigs is associated with porcine idiopathic vesicular disease (PIVD). Outbreaks of SVV infection in pig herds have been reported in several Asia and Americas countries. Recently, a series of outbreaks of SVV infection occurred in China, Canada, Thailand and the United States. However, no available vaccines have been developed to limit the transmission of SVV. The SVV CH-FJ-2017 from Fujian province in China is a representative of the epidemic strains, and shows 98.5-99.9% capsid protein amino acid identity with the recent SVV strains. In the present study, we developed a SVV CH-FJ-2017 inactivated vaccine. The SVV was produced by cultivation of BHK-21 cells in roller bottles, inactivated with binary ethylenimine, and mixed with oil adjuvant (Montanide ISA). The immunogenicity of the inactivated vaccine in pigs was evaluated by neutralizing test, and the immunized pigs were challenged with SVV CH-FJ-2017. The results showed that animals receiving one dose of the inactivated vaccine (2 μg/dose) with oil adjuvant developed high neutralizing antibody titers and showed no clinical signs after virus challenge comparing with the non-vaccinated animals, indicating a good protective efficacy of the produced vaccine against SVV infection. This is the first reported SVV vaccine that can be used for control of SVV infection in pigs.

Keywords: Immunogenicity; Protection; Seneca Valley virus; Vaccine.