Commercial E2 subunit vaccine provides full protection to pigs against lethal challenge with 4 strains of classical swine fever virus genotype 2

Publication date: Available online 30 August 2019Source: Veterinary MicrobiologyAuthor(s): Wenjie Gong, Junhui Li, Zunbao Wang, Jiumeng Sun, Shijiang Mi, Jialun Xu, Jian Cao, Yuzhen Hou, Danyang Wang, Xinliang Huo, Yanjun Sun, Pengjiang Wang, Ke Yuan, Yangyi Gao, Xubin Zhou, Sun He, Changchun TuAbstractClassical swine fever (CSF) still threatens the swine industry in China, with genotype 2 isolates of CSFV dominating the epizootics. In 2018 the first E2 subunit marker vaccine against CSFV (Tian Wen Jing, TWJ-E2®), containing a baculovirus-expressed E2 glycoprotein of a genotype 1.1 vaccine strain, was officially licensed in China and commercialized. To evaluate the cross-protective efficacy of TWJ-E2 against different virulent genotype 2 Chinese field isolates (2.1b, 2.1c, 2.1 h, and 2.2), 4-week-old pigs were immunized with the TWJ-E2 vaccine according to the manufacturer’s instructions and then challenged with genotype 2 strains. A group vaccinated with the conventional C-strain vaccine was included for comparison. TWJ-E2 vaccinated pigs developed higher levels of E2 and neutralizing antibodies than those receiving the commercial C-strain vaccine. All TWJ-E2 and C-strain vaccinated pigs survived challenge without development of fever, clinical signs or pathological lesions. In contrast, all unvaccinated control pigs displayed severe CSF disease with 40-100% mortalities by 24 days post challenge. None of the TWJ-E2 and C-strain vaccinated pigs developed viremia, viral s...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research