Search Results (3)

Seneca Valley virus (SVV), also known as Senecavirus A (SVA), is a non-enveloped and single-strand positive-sense RNA virus, which belongs to the genus of Senecavirus within the family Picornaviridae. Porcine idiopathic vesicular disease (PIVD) caused by SVV has frequently been prevalent in America and Southeast Asia (especially in China) since the end of 2014, and has caused continuing issues. In this study, an SVV strain isolated in China, named SVV LNSY01-2017 (MH064435), was used as the stock virus for the preparation of an SVV-inactivated vaccine. The SVV culture was directly inactivated using binary ethyleneimine (BEI) and β-propiolactone (BPL). BPL showed a better effect as an SVV inactivator, according to the results of pH variation, inactivation kinetics, and the detection of VP1 content during inactivation. Then, SVV inactivated by BPL was subsequently emulsified using different adjuvants, including MONTANIDE^TM ISA 201 VG (ISA 201) and MONTANIDE^TM IMG 1313 VG N (IMS 1313). The immunoreactivity and protection efficacy of the inactivated vaccines were then evaluated in finishing pigs. SVV-BPL-1313 showed a better humoral response post-immunization and further challenge tests post-immunization showed that both the SVV-BPL-201 and SVV-BPL-1313 combinations could resist challenge from a virulent SVV strain. The SVV LNSY01-2017-inactivated vaccine candidate developed here represents a promising alternative to prevent and control SVV infection in swine. Full article

Senecavirus A (SVA) is the pathogen that has recently caused porcine idiopathic vesicular disease (PIVD). The clinical symptoms of PIVD are similar to those of acute foot-and-mouth disease and also can result in the death of newborn piglets, thus entailing economic losses. Vaccine immunization is the most effective way to prevent and control SVA. Among all SVA vaccines reported, only the SVA inactivated vaccine has been successfully developed. However, to ensure the elimination of this pathogen, safer and more effective vaccines are urgently required. A virus-like particles (VLPs)-based vaccine is probably the best alternative to inactivated vaccine. To develop an SVA VLPs vaccine and evaluate its immune effect, a prokaryotic expression system was used to produce SVA capsid protein and assemble VLPs. The VLPs were characterized by affinity chromatography, sucrose density gradient centrifugation, ZetaSizer and transmission electron microscopy. Meanwhile, the SVA CH-HB-2017 strain was used to infect pigs and to determine infection routes and dose. Experimental pigs were then immunized with the SVA VLPs vaccine emulsified in an ISA 201 adjuvant. The results showed that the VLPs vaccine induced neutralizing and specific antibodies at similar levels as an inactivated SVA vaccine after immunization. The level of INF-γ induced by the VLPs vaccine gradually decreased—similar to that of inactivated vaccine. These results indicated that VLPs vaccine may simultaneously cause both cellular and humoral immune responses. Importantly, after the challenge, the VLPs vaccine provided similar levels of protection as the inactivated SVA vaccine. In this study, we successfully obtained novel SVA VLPs and confirmed their highly immunogenicity, thus providing a superior candidate vaccine for defense and elimination of SVA, compared to the inactivated vaccine. Full article

Senecavirus A (SVA), an emerging infectious disease, is associated with the porcine idiopathic vesicular disease. Here, the pathogenesis of different strains of SVA was investigated in growing-finishing pigs. We aimed to evaluate the replication characteristics, virus particle morphology, clinical signs, and vesicular lesions in comparison with two different strains of SVA. The animals were infected with SVA HB-CH-2016 or CH/AH-02/2017 by intranasal routes (3 mL, 10⁹TCID₅₀/mL) and monitored daily for 14 days post-inoculation (dpi) for clinical signs and vesicular lesions. Viremia or viral shedding was detected in the blood, fecal swab, and nasal swab samples. Results showed no distinct differences in plaque size, replication ability, and characteristic virions between SVA HB-CH-2016 and CH/AH-02/2017 strains. Animal experimental results showed that both SVA CH/AH-02/2017 and SVA HB-CH-2016 could infect pigs. However, an obvious difference in the pathogenicity and dynamics of infection was observed between SVA HB-CH-2016 and CH/AH-02/2017 strains. The pathogenesis of SVA CH/AH-02/2017 was similar to that of published results of USA strains, whereas the SVA HB-CH-2016 strain had low pathogenicity to pigs. Clinical signs and vesicular lesions were observed in SVA CH/AH-02/2017-infected pigs. Additionally, the different branches of SVA should be capable of inducing broad cross-reactive neutralizing antibodies, which play an important role in clearing the SVA virus. This study of animal models for SVA infection will be beneficial to develop vaccines and antivirals. Full article