Division of Infectious Diseases of Animals and Veterinary Administration, Department of Epizootiology and Clinic of Birds and Exotic Animals, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, pl. Grunwaldzki 45, 50-366 Wroclaw, Poland.
Department of Virology, National Veterinary Research Institute, al. Partyzantów 57, 24-100 Pulawy, Poland.
Viruses. 2022 Feb 2;14(2):311. doi: 10.3390/v14020311.
The aim of the report was to present the circulation of BVDV (bovine viral diarrhea virus) in the cattle population and determine the cause of the failure of vaccination failure leading to the birth of the PI (persistently infected) calf. The case study was carried out at the BVDV-free animal breeding center and cattle farm, where the vaccination program against BVDV was implemented in 2012, and each newly introduced animal was serologically and virologically tested for BVDV. In this case, a blood sample was taken from a 9-month-old breeding bull. Positive RT-PCR and negative ELISA serology results were obtained. The tests were repeated at 2-week intervals, and the results confirmed the presence of the virus and the absence of specific antibodies, i.e., persistent infection. Additionally, sequencing and phylogenetic analysis were performed, and the BVDV-1d subgenotype was detected. The results of this study showed that pregnant heifers and cows that are vaccinated multiple times with the killed vaccine containing BVDV-1a may not be fully protected against infection with other subgenotypes of BVDV, including their fetuses, which can become PI calves.
本报告旨在介绍牛病毒性腹泻病毒（BVDV）在牛群中的传播情况，并确定导致疫苗接种失败导致 PI（持续感染）小牛出生的原因。该案例研究在 BVDV 无动物繁殖中心和牛场进行，2012 年在这些地方实施了针对 BVDV 的疫苗接种计划，每只新引入的动物都进行了 BVDV 的血清学和病毒学检测。在这种情况下，从一头 9 月龄的种公牛身上采集了血液样本。结果为 RT-PCR 阳性和 ELISA 血清学阴性。每隔两周重复进行这些测试，结果证实了病毒的存在和特定抗体的缺失，即持续感染。此外，还进行了测序和系统发育分析，检测到了 BVDV-1d 亚群。本研究结果表明，多次接种含有 BVDV-1a 的灭活疫苗的怀孕小母牛和母牛可能无法完全免受其他 BVDV 亚群的感染，包括其胎儿，这些胎儿可能成为 PI 小牛。
