{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T15:02:51Z","timestamp":1789570971119,"version":"build-2803163510"},"reference-count":30,"publisher":"Akademiai Kiado Zrt.","issue":"3","content-domain":{"domain":["www.akjournals.com"],"crossmark-restriction":true},"short-container-title":["AVET"],"published-print":{"date-parts":[[2026,9,16]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Porcine reproductive and respiratory syndrome (PRRS) causes severe reproductive losses in pregnant sows and piglets, resulting in substantial economic impact on the swine industry worldwide. However, due to the significant genetic diversity and rapid evolutionary changes of the pathogen, continuous surveillance and detailed genetic analysis of circulating strains are essential. The current study aimed to evaluate the genetic diversity of the hypervariable (HV) region of non-structural protein 2 (nsp2) among North American PRRSV strains isolated from swine farms in Vietnam. Phylogenetic analysis and multiple sequence alignment were conducted to determine subtype classification and assess genetic variability. A total of 48 field isolates were obtained, of which 12.5% belonged to classical NA-PRRSV, 16.6% to NADC30-like and 70.9% to HP-PRRSV, primarily distributed across sublineages 1.4, 5.1, 8.7 and 8.9. Amino acid comparisons found multiple insertions, deletions and substitutions at various positions within the hypervariable region of nsp2. The study revealed substantial genetic variation in the HV region of nsp2 among NA-PRRSV field strains, largely associated with recombination and immune escape. These findings highlight epidemiological risks to vaccine efficacy and underscore the need for continuous molecular surveillance to support effective PRRSV control in Vietnam.<\/jats:p>","DOI":"10.1556\/004.2026.01282","type":"journal-article","created":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T14:00:30Z","timestamp":1788271230000},"page":"196-204","update-policy":"https:\/\/doi.org\/10.1556\/policypage.crossmark.crossref.2","source":"Crossref","is-referenced-by-count":0,"title":["Genetic diversity and recombination of\u00a0NA-PRRSV field strains in Vietnam: Implications for vaccine efficacy"],"prefix":"10.1556","volume":"74","author":[{"given":"Thu-Ha","family":"Le-Thi","sequence":"first","affiliation":[{"name":"Faculty of Biology Sciences, Nong Lam University, Quarter 33, Linh Xuan Ward, Ho Chi Minh City, 71309, Vietnam"},{"name":"VETLATECH Joint Stock Company, Ha Noi, 13219, Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Van-Anh","family":"Huynh-Nguyen","sequence":"additional","affiliation":[{"name":"Laboratory of Biosensors, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, 72711, Vietnam"},{"name":"Department of Molecular and Environmental Biotechnology, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, 72711, Vietnam"},{"name":"Laboratory of Molecular Biotechnology, University of Science, Ho Chi Minh, 7277, Vietnam"},{"name":"Vietnam National University, Thu Duc City, Ho Chi Minh City, 71308, Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tram-Anh","family":"Bui-Nguyen","sequence":"additional","affiliation":[{"name":"Laboratory of Biosensors, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, 72711, Vietnam"},{"name":"Department of Molecular and Environmental Biotechnology, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, 72711, Vietnam"},{"name":"Laboratory of Molecular Biotechnology, University of Science, Ho Chi Minh, 7277, Vietnam"},{"name":"Vietnam National University, Thu Duc City, Ho Chi Minh City, 71308, Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ngoc-Hai","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Department of Infectious Disease and Veterinary Public Health, Faculty of Animal Husbandry and Veterinary Medicine, Nong Lam University, Quarter 33, Linh Xuan Ward, Ho Chi Minh City, 71309, Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuan-Phat","family":"Dinh","sequence":"additional","affiliation":[{"name":"Faculty of Biology Sciences, Nong Lam University, Quarter 33, Linh Xuan Ward, Ho Chi Minh City, 71309, Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Quoc-Vu","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Laboratory of Biosensors, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, 72711, Vietnam"},{"name":"Department of Molecular and Environmental Biotechnology, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, 72711, Vietnam"},{"name":"Laboratory of Molecular Biotechnology, University of Science, Ho Chi Minh, 7277, Vietnam"},{"name":"Vietnam National University, Thu Duc City, Ho Chi Minh City, 71308, Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dieu-Thuy","family":"Nguyen-Thi","sequence":"additional","affiliation":[{"name":"Institute of Biology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Rd., Nghia Do, Ha Noi, 11307, Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2782-5232","authenticated-orcid":true,"given":"Hieu","family":"Tran-Van","sequence":"additional","affiliation":[{"name":"Laboratory of Biosensors, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, 72711, Vietnam"},{"name":"Department of Molecular and Environmental Biotechnology, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, 72711, Vietnam"},{"name":"Laboratory of Molecular Biotechnology, University of Science, Ho Chi Minh, 7277, Vietnam"},{"name":"Vietnam National University, Thu Duc City, Ho Chi Minh City, 71308, Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"425","reference":[{"key":"B1","series-title":"Virus Res.","article-title":"Molecular and cellular mechanisms for PRRSV pathogenesis and host response to infection","volume":"286","author":"An, T.","year":"2020","unstructured":"An, T., Li, J., Su, C. and Yoo, D. (2020): Molecular and cellular mechanisms for PRRSV pathogenesis and host response to infection. Virus Res. 286."},{"issue":"2","key":"B2","series-title":"Virology","first-page":"410","article-title":"Serologic marker candidates identified among B-cell linear epitopes of Nsp2 and structural proteins of a North American strain of porcine reproductive and respiratory syndrome virus","volume":"353","author":"De Lima, M.","year":"2006","unstructured":"De Lima, M., Pattnaik, A. K., Flores, E. F. and Osorio, F. A. (2006): Serologic marker candidates identified among B-cell linear epitopes of Nsp2 and structural proteins of a North American strain of porcine reproductive and respiratory syndrome virus. Virology 353(2), 410\u2013421."},{"issue":"3","key":"B3","series-title":"Vet. Sci. Techniques","article-title":"Comparison of genetic homology among the highly virulent field HP-PPRSV strains isolated from 2009 to 2014 and the PRRSV strains of commercial vaccines","volume":"23","author":"Do, T. D.","year":"2016","unstructured":"Do, T. D. and Nguyen, T. T. (2016): Comparison of genetic homology among the highly virulent field HP-PPRSV strains isolated from 2009 to 2014 and the PRRSV strains of commercial vaccines. Vet. Sci. Techniques 23(3)."},{"issue":"11","key":"B4","series-title":"Emerg. Infect. Dis.","first-page":"1774","article-title":"Porcine respiratory and reproductive syndrome virus variants, Vietnam and China, 2007","volume":"14","author":"Feng, Y.","year":"2008","unstructured":"Feng, Y., Zhao, T., Nguyen, T., Inui, K., Ma, Y., Nguyen, T. H., et\u00a0al. (2008): Porcine respiratory and reproductive syndrome virus variants, Vietnam and China, 2007. Emerg. Infect. Dis. 14(11), 1774\u20131776."},{"key":"B5","series-title":"Front. Vet. Sci.","article-title":"A\u00a0novel L1C.5 RFLP-1-4-4 recombinant porcine reproductive and respiratory syndrome virus between wild-type virus and a modified-live virus vaccine is highly pathogenic to piglets","volume":"12","author":"Gao, X.","year":"2025","unstructured":"Gao, X., Zhou, J., Kang, R., Lu, H., Feng, S., Pei, Y., et\u00a0al. (2025): A\u00a0novel L1C.5 RFLP-1-4-4 recombinant porcine reproductive and respiratory syndrome virus between wild-type virus and a modified-live virus vaccine is highly pathogenic to piglets. Front. Vet. Sci. 12."},{"issue":"2\u20133","key":"B6","series-title":"J.\u00a0Comp. Pathol.","first-page":"135","article-title":"Pathological characterization of an outbreak of porcine reproductive and respiratory syndrome in northern Vietnam","volume":"154","author":"Giang, N. H.","year":"2016","unstructured":"Giang, N. H., Lan, N., Nam, N., Hirai, T. and Yamaguchi, R. 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J. 7(1)."},{"issue":"1","key":"B11","series-title":"Virus Genes","first-page":"118","article-title":"Insertion and deletion in a non-essential region of the nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome (PRRS) virus: effects on virulence and immunogenicity","volume":"38","author":"Kim, D.","year":"2008","unstructured":"Kim, D., Kaiser, T. J., Horlen, K., Keith, M. L., Taylor, L. P., Jolie, R., et\u00a0al. (2008): Insertion and deletion in a non-essential region of the nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome (PRRS) virus: effects on virulence and immunogenicity. Virus Genes 38(1), 118\u2013128."},{"issue":"1","key":"B12","series-title":"BMC Vet. Res.","article-title":"Seroprevalences of multi-pathogen and description of farm movement in pigs in two provinces\u00a0in Vietnam","volume":"16","author":"Lee, H. S.","year":"2020","unstructured":"Lee, H. S., Bui, V. N., Nguyen, H. X., Bui, A. N., Hoang, T. D., Nguyen-Viet, H., et\u00a0al. (2020): Seroprevalences of multi-pathogen and description of farm movement in pigs in two provinces\u00a0in Vietnam. BMC Vet. Res. 16(1)."},{"issue":"9","key":"B13","series-title":"J. Clin. Microbiol.","first-page":"3175","article-title":"Epidemiology and evolutionary characteristics of the porcine reproductive and respiratory syndrome virus in China between 2006 and 2010","volume":"49","author":"Li, B.","year":"2011","unstructured":"Li, B., Fang, L., Guo, X., Gao, J., Song, T., Bi, J., et\u00a0al. (2011): Epidemiology and evolutionary characteristics of the porcine reproductive and respiratory syndrome virus in China between 2006 and 2010. J. Clin. Microbiol. 49(9), 3175\u20133183."},{"issue":"1","key":"B14","series-title":"Open Virol. 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(2025): Economic impact of productivity losses attributable to porcine reproductive and respiratory syndrome virus in United States pork production, 2016\u20132020. Prev. Vet. Med. 244."},{"issue":"4","key":"B20","series-title":"Transbound. Emerg. Dis.","first-page":"1168","article-title":"Financial impacts of priority swine diseases to pig farmers in Red River and Mekong River Delta, Vietnam","volume":"64","author":"Pham, H. T. T.","year":"2016","unstructured":"Pham, H. T. T., Antoine-Moussiaux, N., Grosbois, V., Moula, N., Truong, B. D., Phan, T. D., et\u00a0al. (2016): Financial impacts of priority swine diseases to pig farmers in Red River and Mekong River Delta, Vietnam. Transbound. Emerg. Dis. 64(4), 1168\u20131177."},{"issue":"3","key":"B21","series-title":"Thai J. Vet. 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Evol. 24, 193\u2013201."},{"issue":"10","key":"B27","series-title":"Viruses","first-page":"2174","article-title":"Characterization and pathogenicity of two novel PRRSVs recombined by NADC30-like and NADC34-like strains in China","volume":"14","author":"Wu, Y.","year":"2022","unstructured":"Wu, Y., Peng, O., Xu, Q., Li, Q., Li, W., Lin, L., et\u00a0al. (2022): Characterization and pathogenicity of two novel PRRSVs recombined by NADC30-like and NADC34-like strains in China. Viruses 14(10), 2174."},{"issue":"5","key":"B28","series-title":"Vet. Sci.","first-page":"325","article-title":"Genetic variability and recombination of the NSP2 gene of PRRSV-2 strains in China from 1996 to 2021","volume":"10","author":"Zhang, H.","year":"2023","unstructured":"Zhang, H., Luo, Q., Zheng, Y., Sha, H., Li, G., Kong, W., Huang, L. and Zhao, M. (2023): Genetic variability and recombination of the NSP2 gene of PRRSV-2 strains in China from 1996 to 2021. Vet. Sci. 10(5), 325."},{"key":"B29","series-title":"Front. Microbiol.","article-title":"Recent advances in the study of NADC34-like porcine reproductive and respiratory syndrome virus in China","volume":"13","author":"Zhao, H.","year":"2022","unstructured":"Zhao, H., Wang, F., Han, X., Guo, H., Liu, C., Hou, L., et\u00a0al. (2022): Recent advances in the study of NADC34-like porcine reproductive and respiratory syndrome virus in China. Front. Microbiol. 13."},{"issue":"1","key":"B30","series-title":"Animal Diseases","article-title":"Epidemiological surveillance and economic impact analysis of different porcine reproductive and respiratory syndrome virus infection statuses in 23 breeding pig farms in Hubei, China","volume":"4","author":"Zhao, H.","year":"2024","unstructured":"Zhao, H., Zhou, J., Zhang, M., Yang, X., Xi, Z., Gao, Q., et\u00a0al. (2024): Epidemiological surveillance and economic impact analysis of different porcine reproductive and respiratory syndrome virus infection statuses in 23 breeding pig farms in Hubei, China. Animal Diseases 4(1)."},{"issue":"3","key":"B31","series-title":"Vet. Med. Sci.","first-page":"697","article-title":"Genetic characterization of a novel recombined porcine reproductive and respiratory syndrome virus 2 among Nadc30\u2010like, Jxa1\u2010like and TJ\u2010like strains","volume":"7","author":"Zhao, J.","year":"2020","unstructured":"Zhao, J., Zhu, L., Huang, J., Yang, Z., Xu, L., Gu, S., et\u00a0al. (2020): Genetic characterization of a novel recombined porcine reproductive and respiratory syndrome virus 2 among Nadc30\u2010like, Jxa1\u2010like and TJ\u2010like strains. Vet. Med. Sci. 7(3), 697\u2013704."},{"key":"B32","series-title":"Front. 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