Efficiency Comparison of a Novel E2 Subunit Vaccine and a Classic C-Strain Vaccine against Classical Swine Fever.

Pei Zhou,Qi Li,Rongyu Zeng,Xueying Fu,Hui Chen,Xiangqi Hao,Junming Huang,Guihong Zhang,Yanchao Li,Yidan Wu

doi:10.3390/vetsci8080148

Abstract

Classical swine fever (CSF) is one of the most important viral diseases in swine, causing severe economic losses in the swine industry. In China, CSF is one of the key diseases that needs to be controlled; the government has implemented control measures, and vaccination with C-strain vaccines (C-vacs) has been compulsory since the 1950s. C-vacs do not allow the differentiation of field virus-infected and vaccinated animals (DIVA). In 2012, China proposed a goal of eradicating CSF. Additionally, a baculovirus-expressed E2 subunit vaccine (E2-vac) was licensed in 2018. However, the C-vac and E2-vac characteristics have not been compared. Here, we demonstrate that both the C-vac and E2-vac provide complete protection against CSF in pigs. The E2-vac allows DIVA, and the E2 antibody responses of stimulated pigs are developed earlier and are stronger than the C-vac antibody responses. Therefore, the E2-vac is a new candidate licensed vaccine to completely eradicate CSF on pig farms.

Highlights

Classical swine fever (CSF) is one of the most important viral diseases in swine, including wild boar
CSF is caused by the classical swine fever virus (CSFV), a member of the Pestivirus genus within the Flaviviridae family [1]
In the infection control group, two piglets died at 13 days post challenge, and one piglet died at 16 dpc (Figure 2A); the remaining two piglets were euthanized due to severe clinical symptoms, including fever (Figure 2B), anorexia, labored breathing, and astasia at 56 dpv

Summary

Introduction

Classical swine fever (CSF) is one of the most important viral diseases in swine, including wild boar. The translated polyprotein is processed by viral and cellular proteases to form 12 mature proteins, four of which are structural (core protein (C) and envelope glycoproteins E0, E1, and E2) and eight of which are nonstructural (Npro, p7, NS2, NS3, NS4A, NS4B, NS5A, and NS5B) [2]. Among these proteins, E2 is a multi-functional glycoprotein that plays roles in viral attachment, viral replication and host immunoreactions [3,4,5,6]. The E2 protein is the major protective antigen inducing neutralizing antibody in the host [7], and has been selected as the most effective immunogen for development of subunit vaccines against CSFV [7,8,9,10]

Methods

Results

Conclusion