Selection of Vaccine Candidate for Foot-and-Mouth Disease Virus Serotype O Using a Blocking Enzyme-Linked Immunosorbent Assay.

Kun Li,Yimei Cao,Huifang Bao,Xiangchuan Xing,Pinghua Li,Nana Huang,Xueqing Ma,Guoqiang Zhu,Jing Zhang,Pu Sun,Zengjun Lu,Yuanfang Fu,Zaixin Liu,Dong Li,Xingwen Bai

doi:10.3390/vaccines9040387

Abstract

Foot-and-mouth disease (FMD) is a highly contagious disease and one of the most economically important diseases of livestock. Vaccination is an important measure to control FMD and selection of appropriate vaccine strains is crucial. The objective of this study was to select a vaccine candidate and to evaluate the potential of a blocking ELISA for detecting neutralizing antibodies (NA-ELISA) in vaccine strain selection. Binary ethylenimine inactivated vaccines, prepared from four representative circulating strains (FMDV O/Mya/98, SCGH/CHA/2016, O/Tibet/99, and O/XJ/CHA/2017) belonging to four lineages within three different topotypes of FMD virus (FMDV) serotype O in China, were used to vaccinate cattle (12–13 animals for each strain), sheep (12–13 animals for each strain), and pigs (10 animals for each strain). The results of immunogenicity comparison showed that O/XJ/CHA/2017 exhibited the highest immunogenicity among the four strains in pigs, cattle, and sheep both by NA-ELISA and virus neutralizing test (VNT). Cross-neutralization analysis indicated that O/XJ/CHA/2017 displayed broad antigen spectrum and was antigenically matched with other three representative strains both by NA-ELISA and VNT. In addition, A significant correlation (p < 0.0001) was observed between the NA-ELISA titers and the VNT titers for four representative strains. The results showed that O/XJ/CHA/2017 was a promising vaccine strain candidate and NA-ELISA was comparable to VNT in neutralizing antibodies detection and could be used as the reference test system for vaccine strain selection.

Highlights

Foot-and-mouth disease (FMD) is a highly contagious viral disease affecting clovenhoofed animals such as cattle, pigs, sheep, goats, and about 70 species of wild animal
The causative agent, FMD virus (FMDV), is a single-stranded, positive-sense RNA virus belonging to the Aphthovirus genus of the family Picornaviridae
Among the seven serotypes of FMDV, serotype O is the most widely distributed in the world

Summary

Introduction

Foot-and-mouth disease (FMD) is a highly contagious viral disease affecting clovenhoofed animals such as cattle, pigs, sheep, goats, and about 70 species of wild animal. It leads to enormous economic losses due to severe reduction in animal productivity, high mortality in newborn animals and trade restriction on affected countries [1,2]. The virus exists as seven distinct serotypes (A, O, C, Asia 1, SAT1, SAT2, and SAT3) with each serotype containing multiple and constantly evolving strains [3,4]. Among the seven serotypes of FMDV, serotype O is the most widely distributed in the world

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