Evaluation of the Efficacy of a Recombinant Adenovirus Expressing the Spike Protein of Porcine Epidemic Diarrhea Virus in Pigs

Liu, Xinsheng; Zhao, Donghong; Zhou, Peng; Zhang, Yongguang; Wang, Yonglu

Porcine epidemic diarrhea virus (PEDV), a member of the order Nidovirales, family Coronaviridae, and genus Alphacoronavirus, is the causative agent of porcine epidemic diarrhea (PED), which is characterized by watery diarrhea, vomiting, dehydration, growth retardation, and high morbidity and mortality in suckling piglets [1, 2] . PEDV is an enveloped, single-stranded, positive-sense RNA virus, and its genome is approximately 28 kb in length and is composed of seven open reading frames (ORF1a, ORF1b, and ORF2-6) [3, 4] . Four structural proteins, namely, the spike (S) glycoprotein, membrane (M) protein, envelope (E) protein, and nucleocapsid (N) protein, and one accessory protein, ORF3, are encoded by ORF2-6 [4, 5] . Among the structural proteins, the S protein is the major envelope glycoprotein responsible for receptor binding and cell membrane fusion and entry [6, 7] . erefore, the S protein is considered the main target for neutralizing antibodies against PEDV and has been frequently used in phylogenetic analysis, establishment of serologic diagnostic methods, and development of new vaccines.