{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:30:59Z","timestamp":1760236259972,"version":"build-2065373602"},"reference-count":51,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,11,13]],"date-time":"2021-11-13T00:00:00Z","timestamp":1636761600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>The high antigenic diversity of porcine epidemic diarrhea virus (PEDV) means that porcine epidemic diarrhea (PED) is a challenge for the global pig industry. Understanding the circulation of the virus to determine an optimal vaccine strategy is important in controlling the disease. In this study, we describe the genetic diversity of circulating PEDV based on the full sequences of spike genes of eight positive samples collected in Vietnam since 2018. Additionally, we developed a live attenuated vaccine candidate from the cell-adapted PEDV2 strain, which was continuously passaged until level 103 in VERO-CCL81 cells. PEDV2-p103, which belongs to the emerging non-S INDEL cluster, exhibited low virus shedding, did not induce lesions in the small intestine of challenged piglets, and had a high titer in the VERO-CCL81 cell at 48 h post-infection. These results suggest that the PEDV2-p103 strain could be a potential oral attenuated vaccine, and its immunogenicity and efficacy should be further assessed through in vivo tests.<\/jats:p>","DOI":"10.3390\/pathogens10111479","type":"journal-article","created":{"date-parts":[[2021,11,14]],"date-time":"2021-11-14T20:51:53Z","timestamp":1636923113000},"page":"1479","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Characteristics and Pathogenicity of the Cell-Adapted Attenuated Porcine Epidemic Diarrhea Virus of the Non-S INDEL Cluster"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1757-2171","authenticated-orcid":false,"given":"Thi Thu Hang","family":"Vu","sequence":"first","affiliation":[{"name":"College of Pharmacy, Korea University, Sejong 30019, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8949-6361","authenticated-orcid":false,"given":"Minjoo","family":"Yeom","sequence":"additional","affiliation":[{"name":"College of Pharmacy, Korea University, Sejong 30019, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hyoungjoon","family":"Moon","sequence":"additional","affiliation":[{"name":"College of Healthcare & Biotechnology, Semyung University, Jecheon 27136, Korea"},{"name":"Research Unit, Green Cross Veterinary Products, Yongin 17066, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thi Nhan","family":"Tran","sequence":"additional","affiliation":[{"name":"R&D laboratory, AVAC Vietnam Company Limited, Hung Yen 163530, Vietnam"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Van Phan","family":"Le","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 131001, Vietnam"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daesub","family":"Song","sequence":"additional","affiliation":[{"name":"College of Pharmacy, Korea University, Sejong 30019, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1007\/BF01317606","article-title":"A new coronavirus-like particle associated with diarrhea in swine","volume":"58","author":"Pensaert","year":"1978","journal-title":"Arch. Virol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.virusres.2016.05.023","article-title":"Evolution, antigenicity and pathogenicity of global porcine epidemic diarrhea virus strains","volume":"226","author":"Lin","year":"2016","journal-title":"Viruses Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"161","DOI":"10.3201\/eid1801.111259","article-title":"Outbreak of porcine epidemic diarrhea in suckling piglets, China","volume":"18","author":"Sun","year":"2012","journal-title":"Emerg. Infect. Dis."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"166","DOI":"10.7774\/cevr.2015.4.2.166","article-title":"Porcine epidemic diarrhea: A review of current epidemiology and available vaccines","volume":"4","author":"Song","year":"2015","journal-title":"Clin. Exp. Vaccine Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"781","DOI":"10.1007\/978-1-4615-5331-1_101","article-title":"Further analysis of the genome of porcine epidemic diarrhoea virus","volume":"440","author":"Bridgen","year":"1998","journal-title":"Adv. Exp. Med. Biol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1195","DOI":"10.1099\/0022-1317-75-5-1195","article-title":"Sequence of the spike protein of the porcine epidemic diarrhoea virus","volume":"75","author":"Duarte","year":"1994","journal-title":"J. Gen. Virol."},{"key":"ref_7","first-page":"1320","article-title":"Characterization of the structural proteins of porcine epizootic diarrhea virus, strain CV777","volume":"49","author":"Egberink","year":"1988","journal-title":"Am. J. Vet. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1023\/A:1011831902219","article-title":"Completion of the porcine epidemic diarrhoea coronavirus (PEDV) genome sequence","volume":"23","author":"Kocherhans","year":"2001","journal-title":"Virus Gen."},{"key":"ref_9","unstructured":"Straw, B.E., Zimmerman, J.J., D\u2019Allaire, S., and Taylor, D.J. (2006). Porcine Epidemic Diarrhea. Disease of Swine, Wiley-Blackwell. [9th ed.]."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Kaewborisuth, C., He, Q., and Jongkaewwattana, A. (2018). The Accessory Protein ORF3 Contributes to Porcine Epidemic Diarrhea Virus Replication by Direct Binding to the Spike Protein. Viruses, 10.","DOI":"10.3390\/v10080399"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Si, F., Hu, X., Wang, C., Chen, B., Wang, R., Dong, S., Yu, R., and Li, Z. (2020). Porcine Epidemic Diarrhea Virus (PEDV) ORF3 Enhances Viral Proliferation by Inhibiting Apoptosis of Infected Cells. Viruses, 12.","DOI":"10.3390\/v12020214"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"384","DOI":"10.1016\/j.febslet.2012.01.005","article-title":"PEDV ORF3 encodes an ion channel protein and regulates virus production","volume":"586","author":"Wang","year":"2012","journal-title":"FEBS Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.virusres.2016.05.031","article-title":"Cellular entry of the porcine epidemic diarrhea virus","volume":"226","author":"Li","year":"2016","journal-title":"Viruses Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"7952","DOI":"10.1128\/JVI.00297-14","article-title":"Proteolytic activation of the porcine epidemic diarrhea coronavirus spike fusion protein by trypsin in cell culture","volume":"88","author":"Wicht","year":"2014","journal-title":"J. Virol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1007\/s00705-010-0892-9","article-title":"Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea","volume":"156","author":"Park","year":"2011","journal-title":"Arch. Virol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.meegid.2017.02.014","article-title":"Evolutionary and epidemiological analyses based on spike genes of porcine epidemic diarrhea virus circulating in Thailand in 2008\u20132015","volume":"50","author":"Stott","year":"2017","journal-title":"Infect. Genet. Evol."},{"key":"ref_17","first-page":"9","article-title":"Genetic Characterization of Porcine Epidemic Diarrhea Virus (PEDV) Isolates from Southern Vietnam during 2009\u20132010 Outbreaks","volume":"41","author":"Do","year":"2011","journal-title":"Isr. J. Vet. Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1292\/jvms.54.313","article-title":"Isolation and Serial Propagation of Porcine Epidemic Diarrhea Virus in Cell Cultures and Partial Characterization of the Isolate","volume":"54","author":"Kusanagi","year":"1992","journal-title":"J. Vet. Med. Sci."},{"key":"ref_19","first-page":"249","article-title":"Isolation of porcine epidemic diarrhea virus (PEDV) in Korea","volume":"33","author":"Kweon","year":"1993","journal-title":"Korean J. Vet. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1007\/s11262-012-0713-1","article-title":"Porcine epidemic diarrhoea virus: A comprehensive review of molecular epidemiology, diagnosis, and vaccines","volume":"44","author":"Song","year":"2012","journal-title":"Viruses Gen."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1292\/jvms1939.45.829","article-title":"An outbreak of swine diarrhea of a new-type associated with coronavirus-like particles in Japan","volume":"45","author":"Takahashi","year":"1983","journal-title":"Nihon Juigaku Zasshi"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1016\/S1016-8478(23)15106-5","article-title":"Identification of the epitope region capable of inducing neutralizing antibodies against the porcine epidemic diarrhea virus","volume":"14","author":"Chang","year":"2002","journal-title":"Mol. Cells"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1016\/j.virusres.2007.10.015","article-title":"The GPRLQPY motif located at the carboxy-terminal of the spike protein induces antibodies that neutralize Porcine epidemic diarrhea virus","volume":"132","author":"Cruz","year":"2008","journal-title":"Viruses Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.vetmic.2008.02.022","article-title":"Identification of two novel B cell epitopes on porcine epidemic diarrhea virus spike protein","volume":"131","author":"Sun","year":"2008","journal-title":"Vet. Microbiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1057","DOI":"10.1007\/s00705-013-1929-7","article-title":"Phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field strains in central China based on the ORF3 gene and the main neutralization epitopes","volume":"159","author":"Li","year":"2014","journal-title":"Arch. Viruses"},{"key":"ref_26","first-page":"1749","article-title":"MERS-coronavirus replication induces severe in vitro cytopathology and is strongly inhibited by cyclosporin A or interferon-\u03b1 treatment","volume":"94","author":"Raj","year":"2013","journal-title":"J. Gen. Viruses"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.jviromet.2006.07.023","article-title":"Identification of cell lines permissive for human coronavirus NL63","volume":"138","author":"Schildgen","year":"2006","journal-title":"J. Viruses Met."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1038\/s41586-020-2012-7","article-title":"A pneumonia outbreak associated with a new coronavirus of probable bat origin","volume":"579","author":"Zhou","year":"2020","journal-title":"Nature"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.vetmic.2019.03.009","article-title":"Assessment of the safety and efficacy of an attenuated live vaccine based on highly virulent genotype 2b porcine epidemic diarrhea virus in nursing piglets","volume":"231","author":"Jang","year":"2019","journal-title":"Vet. Microbiol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.rvsc.2006.03.007","article-title":"Oral efficacy of Vero cell attenuated porcine epidemic diarrhea virus DR13 strain","volume":"82","author":"Song","year":"2007","journal-title":"Res. Vet. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e32","DOI":"10.4142\/jvs.2019.20.e32","article-title":"Generation and protective efficacy of a cold-adapted attenuated genotype 2b porcine epidemic diarrhea virus","volume":"20","author":"Won","year":"2019","journal-title":"J. Vet. Sci."},{"key":"ref_32","first-page":"121","article-title":"Characterization and pathogenicity of Vero cell-attenuated porcine epidemic diarrhea virus CT strain","volume":"16","author":"Wu","year":"2019","journal-title":"Viruses J."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"e83","DOI":"10.1111\/tbed.12681","article-title":"Appearance of US-like porcine epidemic diarrhoea virus (PEDV) strains before US outbreaks and genetic heterogeneity of PEDVs collected in Northern Vietnam during 2012\u20132015","volume":"65","author":"Diep","year":"2018","journal-title":"Transbound. Emerg. Dis."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1002\/vms3.256","article-title":"Genetic characterization of the spike gene of porcine epidemic diarrhea viruses (PEDVs) circulating in Vietnam from 2015 to 2016","volume":"6","author":"Than","year":"2020","journal-title":"Vet. Med. Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1186\/s12917-018-1409-0","article-title":"Molecular characterization of US-like and Asian non-S INDEL strains of porcine epidemic diarrhea virus (PEDV) that circulated in Japan during 2013\u20132016 and PEDVs collected from recurrent outbreaks","volume":"14","author":"Sueyoshi","year":"2018","journal-title":"BMC Vet. Res."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"883","DOI":"10.1111\/tbed.12825","article-title":"Genetic epidemiology of porcine epidemic diarrhoea virus circulating in China in 2012\u20132017 based on spike gene","volume":"65","author":"Wen","year":"2018","journal-title":"Transbound. Emerg. Dis."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"104553","DOI":"10.1016\/j.micpath.2020.104553","article-title":"Porcine epidemic diarrhea virus: Molecular mechanisms of attenuation and vaccines","volume":"149","author":"Li","year":"2020","journal-title":"Microb. Pathog."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1007\/s11262-011-0617-5","article-title":"Mutations in the spike gene of porcine epidemic diarrhea virus associated with growth adaptation in vitro and attenuation of virulence in vivo","volume":"43","author":"Sato","year":"2011","journal-title":"Viruses Gen."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"2546","DOI":"10.1016\/S0264-410X(99)00059-6","article-title":"Derivation of attenuated porcine epidemic diarrhea virus (PEDV) as vaccine candidate","volume":"17","author":"Kweon","year":"1999","journal-title":"Vaccine"},{"key":"ref_40","first-page":"1","article-title":"Porcine epidemic diarrhea virus: Current insights","volume":"8","author":"Lv","year":"2016","journal-title":"Viruses Adapt. Treat."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Won, H., Lim, J., Noh, Y.H., Yoon, I., and Yoo, H.S. (2020). Efficacy of Porcine Epidemic Diarrhea Vaccines: A Systematic Review and Meta-Analysis. Vaccine, 8.","DOI":"10.3390\/vaccines8040642"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"e01451-15","DOI":"10.1128\/mBio.01451-15","article-title":"Characterization of a Pathogenic Full-Length cDNA Clone and Transmission Model for Porcine Epidemic Diarrhea Virus Strain PC22A","volume":"7","author":"Beall","year":"2016","journal-title":"mBio"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.virol.2018.02.019","article-title":"Aminopeptidase-N-independent entry of porcine epidemic diarrhea virus into Vero or porcine small intestine epithelial cells","volume":"517","author":"Ji","year":"2018","journal-title":"Virology"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1016\/j.virusres.2017.03.018","article-title":"Aminopeptidase N is not required for porcine epidemic diarrhea virus cell entry","volume":"235","author":"Li","year":"2017","journal-title":"Viruses Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1016\/j.jviromet.2007.06.021","article-title":"Multiplex real-time RT-PCR for the simultaneous detection and quantification of transmissible gastroenteritis virus and porcine epidemic diarrhea virus","volume":"146","author":"Kim","year":"2007","journal-title":"J. Virol. Met."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1007\/s11262-007-0164-2","article-title":"Cloning and further sequence analysis of the ORF3 gene of wild- and attenuated-type porcine epidemic diarrhea viruses","volume":"36","author":"Park","year":"2008","journal-title":"Viruses Gen."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1007\/s11262-006-0036-1","article-title":"Cloning and further sequence analysis of the spike gene of attenuated porcine epidemic diarrhea virus DR13","volume":"35","author":"Park","year":"2007","journal-title":"Viruses Gen."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"2235","DOI":"10.1128\/jcm.26.11.2235-2239.1988","article-title":"Propagation of the virus of porcine epidemic diarrhea in cell culture","volume":"26","author":"Hofmann","year":"1988","journal-title":"J. Clin. Microbiol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"480","DOI":"10.1007\/BF01863914","article-title":"Beitrag zur kollektiven Behandlung pharmakologischer Reihenversuche","volume":"162","year":"1931","journal-title":"Naunyn-Schmiedebergs Archiv f\u00fcr experimentelle pathologie und pharmakologie"},{"key":"ref_50","first-page":"227","article-title":"The method of \u2018right and wrong cases\u2019 (\u2018constant stimuli\u2019) without gauss\u2019s formulae","volume":"2","author":"Spearman","year":"1908","journal-title":"Br. J. Psychol."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2725","DOI":"10.1093\/molbev\/mst197","article-title":"MEGA6: Molecular Evolutionary Genetics Analysis version 6.0","volume":"30","author":"Tamura","year":"2013","journal-title":"Mol. Biol. Evol."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/10\/11\/1479\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:29:52Z","timestamp":1760167792000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/10\/11\/1479"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,13]]},"references-count":51,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["pathogens10111479"],"URL":"https:\/\/doi.org\/10.3390\/pathogens10111479","relation":{},"ISSN":["2076-0817"],"issn-type":[{"type":"electronic","value":"2076-0817"}],"subject":[],"published":{"date-parts":[[2021,11,13]]}}}