Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology Ministry of Agriculture, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, 210014, China; College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology Ministry of Agriculture, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, 210014, China.
Microb Pathog. 2024 Jul;192:106714. doi: 10.1016/j.micpath.2024.106714. Epub 2024 May 25.
Porcine deltacoronavirus (PDCoV), a novel enteropathogenic coronavirus, causes diarrhea mainly in suckling piglets and has the potential to infect humans. Whereas, there is no commercially available vaccine which can effectively prevent this disease. In this study, to ascertain the duration of immune protection of inactivated PDCoV vaccine, suckling piglets were injected subcutaneously with inactivated PDCoV vaccine using a prime/boost strategy at 3 and 17-day-old. Neutralizing antibody assay showed that the level of the inactivated PDCoV group was still ≥1:64 at three months after prime vaccination. The three-month-old pigs were orally challenged with PDCoV strain CZ2020. Two pigs in challenge control group showed mild to severe diarrhea at 10-11 day-post-challenge (DPC), while the inactivated PDCoV group had no diarrhea. High levels of viral shedding, substantial intestinal villus atrophy, and positive straining of viral antigens in ileum were detected in challenge control group, while the pigs in inactivated PDCoV group exhibited significantly reduced viral load, minor intestinal villi damage and negative straining of viral antigens. These results demonstrated that PDCoV was pathogenic against three-month-old pigs and inactivated PDCoV vaccine can provide effective protection in pigs lasting for three months.
猪德尔塔冠状病毒（PDCoV）是一种新型的肠致病性冠状病毒，主要引起仔猪腹泻，并有可能感染人类。然而，目前还没有可商售的疫苗能够有效预防这种疾病。在本研究中，为了确定灭活 PDCoV 疫苗的免疫保护持续时间，采用首免和加强免疫策略，于 3 日龄和 17 日龄时对仔猪进行皮下注射灭活 PDCoV 疫苗。中和抗体检测结果表明，首免后 3 个月，灭活 PDCoV 组的抗体效价仍≥1:64。3 月龄仔猪经口感染 PDCoV 分离株 CZ2020。攻毒对照组的 2 头仔猪在攻毒后 10-11 天出现轻度至重度腹泻，而灭活 PDCoV 组无腹泻症状。攻毒对照组仔猪的病毒脱落量高，小肠绒毛萎缩严重，回肠组织中病毒抗原阳性染色，而灭活 PDCoV 组仔猪的病毒载量显著降低，小肠绒毛损伤轻微，病毒抗原阴性染色。这些结果表明，PDCoV 对 3 月龄仔猪具有致病性，灭活 PDCoV 疫苗可提供 3 个月的有效保护。
