Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, No, 1, Sec, 4, Roosevelt Rd,, Taipei 106, Taiwan.
Vet Res. 2011 Dec 1;42(1):115. doi: 10.1186/1297-9716-42-115.
The Lapinized Philippines Coronel (LPC) vaccine, an attenuated strain of classical swine fever virus (CSFV), is an important tool for the prevention and control of CSFV infection and is widely and routinely used in most CSF endemic areas, including Taiwan. The aim of this study was to investigate whether PCV2 infection affects the efficacy of the LPC vaccine. Eighteen 6-week-old, cesarean-derived and colostrum-deprived (CDCD), crossbred pigs were randomly assigned to four groups. A total of 10(5.3) TCID50 of PCV2 was experimentally inoculated into pigs through both intranasal and intramuscular routes at 0 days post-inoculation (dpi) followed by LPC vaccination 12 days later. All the animals were challenged with wild-type CSFV (ALD stain) at 27 dpi and euthanized at 45 dpi. Following CSFV challenge, the LPC-vaccinated pigs pre-inoculated with PCV2 showed transient fever, viremia, and viral shedding in the saliva and feces. The number of IgM(+), CD4(+)CD8-CD25(+), CD4(+)CD8(+)CD25(+), and CD4(-)CD8(+)CD25(+) lymphocyte subsets and the level of neutralizing antibodies against CSFV were significantly higher in the animals with LPC vaccination alone than in the pigs with PCV2 inoculation/LPC vaccination. In addition, PCV2-derived inhibition of the CSFV-specific cell proliferative response of peripheral blood mononuclear cells (PBMCs) was demonstrated in an ex vivo experiment. These findings indicate that PCV2 infection decreases the efficacy of the LPC vaccine. This PCV2-derived interference may not only allow the invasion of wild-type CSFV in pig farms but also increases the difficulty of CSF prevention and control in CSF endemic areas.
拉宾化菲律宾科罗内尔（LPC）疫苗是一种减毒的经典猪瘟病毒（CSFV）株，是预防和控制 CSFV 感染的重要工具，广泛且常规地应用于大多数 CSF 流行地区，包括台湾地区。本研究旨在探讨 PCV2 感染是否会影响 LPC 疫苗的效力。将 18 头 6 周龄、剖腹产和初乳剥夺（CDCD）、杂交猪随机分为 4 组。在 0 天接种后（dpi），通过鼻腔内和肌肉内途径共接种 10（5.3）TCID50 的 PCV2，12 天后接种 LPC 疫苗。所有动物均在 27 dpi 时用野生型 CSFV（ALD 株）攻毒，并在 45 dpi 时安乐死。CSFV 攻毒后，预先接种 PCV2 再接种 LPC 的猪只出现短暂发热、病毒血症和唾液及粪便中的病毒脱落。单独接种 LPC 的猪只的 IgM(+)、CD4(+)CD8-CD25(+)、CD4(+)CD8(+)CD25(+)和 CD4(-)CD8(+)CD25(+)淋巴细胞亚群数量以及针对 CSFV 的中和抗体水平明显高于接种 PCV2/LPC 疫苗的猪只。此外，在体外实验中证明了 PCV2 抑制外周血单核细胞（PBMCs）对 CSFV 特异性细胞增殖反应的能力。这些发现表明，PCV2 感染降低了 LPC 疫苗的效力。这种 PCV2 衍生的干扰不仅可能允许野生型 CSFV 在猪场中入侵，还可能增加 CSF 流行地区 CSF 预防和控制的难度。
