{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T16:04:55Z","timestamp":1779379495923,"version":"3.53.1"},"reference-count":26,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T00:00:00Z","timestamp":1779321600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Beijing City Natural Science Foundation Project","award":["L252074"],"award-info":[{"award-number":["L252074"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Japanese encephalitis virus (JEV) comprises a single serotype but can be classified into five genotypes (genotypes I\u2013V, GI\u2013GV) based on nucleic acid sequences. Historically, genotype III (GIII) was the predominant strain. However, since the 21st century, genotype I (GI) rapidly replaced GIII as the major genotype in China, Southeast Asia, and other regions. The live attenuated vaccine (LAV) SA14-14-2, licensed in China in 1988, was successfully exported to 13 countries, with cumulative vaccinations exceeding one billion doses. The vaccine seed virus SA14-14-2 belonged to genotype III. Whether this GIII-based vaccine provided sufficient protection against the currently circulating GI strains warranted systematic investigation. In this study, recent JEV isolates collected from China were subjected to genotypic analysis, followed by comprehensive evaluations including protective efficacy against challenge and serum neutralizing antibody levels. The results indicated that, despite antigenic differences between GIII and GI strains, no significant differences in protective efficacy post-challenge were observed. The SA14-14-2 LAV remained effective in preventing GI strain infection.<\/jats:p>","DOI":"10.3390\/v18050582","type":"journal-article","created":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T15:02:27Z","timestamp":1779375747000},"page":"582","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Study on the Protective Efficacy of the Japanese Encephalitis Live Attenuated Vaccine SA14-14-2 Against Newly Isolated Genotype I Japanese Encephalitis Viruses"],"prefix":"10.3390","volume":"18","author":[{"given":"Shuai","family":"Shang","sequence":"first","affiliation":[{"name":"National Key Laboratory of Drug Regulatory Science, National Institutes for Food and Drug Control, Beijing 102629, China"},{"name":"Changchun Institute of Biological Products Co., Ltd., Changchun 130015, China"},{"name":"State Key Laboratory of Novel Vaccines for Emerging Infectious Diseases, Beijing 100024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8239-0214","authenticated-orcid":false,"given":"Qikai","family":"Yin","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tingyi","family":"Che","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Drug Regulatory Science, National Institutes for Food and Drug Control, Beijing 102629, China"},{"name":"Changchun Institute of Biological Products Co., Ltd., Changchun 130015, China"},{"name":"State Key Laboratory of Novel Vaccines for Emerging Infectious Diseases, Beijing 100024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinzhu","family":"Wang","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Drug Regulatory Science, National Institutes for Food and Drug Control, Beijing 102629, China"},{"name":"Changchun Institute of Biological Products Co., Ltd., Changchun 130015, China"},{"name":"State Key Laboratory of Novel Vaccines for Emerging Infectious Diseases, Beijing 100024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qi","family":"Su","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Drug Regulatory Science, National Institutes for Food and Drug Control, Beijing 102629, China"},{"name":"Changchun Institute of Biological Products Co., Ltd., Changchun 130015, China"},{"name":"State Key Laboratory of Novel Vaccines for Emerging Infectious Diseases, Beijing 100024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shihong","family":"Fu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongshan","family":"Xu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Drug Regulatory Science, National Institutes for Food and Drug Control, Beijing 102629, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongxin","family":"Yu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Drug Regulatory Science, National Institutes for Food and Drug Control, Beijing 102629, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qunying","family":"Mao","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Drug Regulatory Science, National Institutes for Food and Drug Control, Beijing 102629, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6245-2027","authenticated-orcid":false,"given":"Huanyu","family":"Wang","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinyu","family":"Liu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Drug Regulatory Science, National Institutes for Food and Drug Control, Beijing 102629, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6450","DOI":"10.1128\/JVI.77.11.6450-6465.2003","article-title":"Development and application of a reverse genetics system for Japanese encephalitis virus","volume":"77","author":"Yun","year":"2003","journal-title":"J. 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