{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T05:19:39Z","timestamp":1787721579513,"version":"build-2784847793"},"reference-count":24,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T00:00:00Z","timestamp":1787529600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005046","name":"Heilongjiang Provincial Natural Science Foundation of China","doi-asserted-by":"crossref","award":["ZD2025C008"],"award-info":[{"award-number":["ZD2025C008"]}],"id":[{"id":"10.13039\/501100005046","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background\/Objectives: Classical swine fever (CSF) and pseudorabies (PR), caused by classical swine fever virus (CSFV) and pseudorabies virus (PRV) respectively, are economically significant viral diseases worldwide that severely compromise swine health and constrain international trade. Previously, we generated a recombinant PRV (rPRVTJ-UL44-E2) expressing the CSFV E2 protein that elicited rapid E2-specific antibody responses in rabbits as early as 7 days post-immunization (dpi). However, its immunogenicity and protective efficacy in pigs remain uncharacterized. In this study, we evaluated the protective performance of rPRVTJ-UL44-E2 in pigs via needle-free immunization. Methods: Pigs (n = 5) received a prime immunization with 107 median tissue culture infective doses (TCID50) of rPRVTJ-UL44-E2 via needle-free immunization, followed by a boost immunization with the same dose at 21 dpi, and were then challenged with 105 TCID50 of the virulent CSFV Shimen strain (CSFV-SM) at 33 dpi. Results: Pigs immunized with rPRVTJ-UL44-E2 developed E2-specific antibodies (blocking rates &gt; cutoff value (40%) at 25 dpi) and gB-specific antibodies that were detectable as early as 7 dpi, with anti-CSFV neutralizing antibody titers comparable to those induced by the C-strain vaccine and anti-PRV neutralizing antibody titers also reaching detectable levels at 28 dpi, whereas no specific antibodies were detected in the DMEM control group. All pigs immunized with rPRVTJ-UL44-E2 and C-strain survived the lethal CSFV challenge with no clinical signs or detectable viremia. In contrast all DMEM control pigs succumbed to infection within 9 days post-challenge (dpc). Conclusions: These findings demonstrate that needle-free delivery of rPRVTJ-UL44-E2 confers complete protection against lethal CSFV challenge in pigs.<\/jats:p>","DOI":"10.3390\/vaccines14090730","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T17:20:28Z","timestamp":1787592028000},"page":"730","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Recombinant Pseudorabies Virus Expressing Classical Swine Fever Virus (CSFV) E2 Protein Confers Complete Protection Against Lethal CSFV Challenge via Needle-Free Immunization"],"prefix":"10.3390","volume":"14","author":[{"given":"Ruojia","family":"Huang","sequence":"first","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiang","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"},{"name":"College of Animal Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-7101-0695","authenticated-orcid":false,"given":"Caoyuan","family":"Ma","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"},{"name":"Henan Institute of Science and Technology, Xinxiang 453003, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin","family":"Song","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0834-4372","authenticated-orcid":false,"given":"Tao","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiaoer","family":"Zhang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chunhao","family":"Jiang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"},{"name":"College of Animal Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rui","family":"Luo","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongfeng","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4880-5687","authenticated-orcid":false,"given":"Hua-Ji","family":"Qiu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuan","family":"Sun","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"},{"name":"College of Animal Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, China"},{"name":"Henan Institute of Science and Technology, Xinxiang 453003, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9653-5533","authenticated-orcid":false,"given":"Lian-Feng","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongxia","family":"Wu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/S0378-1135(00)00137-1","article-title":"Introduction to classical swine fever: Virus, disease and control policy","volume":"73","author":"Moennig","year":"2000","journal-title":"Vet. 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