Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
Vet Res. 2014 Feb 2;45(1):13. doi: 10.1186/1297-9716-45-13.
The objective of this study was to evaluate the effect of porcine circovirus type 2 (PCV2) vaccines on PCV2-viremic and -seropositive piglets born from naturally PCV2-infected sows against postnatal PCV2 challenge. The experimental design was aimed at mimicking commercial swine rearing conditions to evaluate the response of the PCV2 vaccine on PCV2-viremic and -seropositive piglets after experimental PCV2 challenge. PCV2a (or 2b)-viremic piglets received a PCV2 vaccine at 21 days of age followed by a PCV2b (or 2a) challenge at 49 days of age (28 days post vaccination). The PCV2 vaccines elicited a high level of humoral (as measured by immunoperoxidase monolayer assay and neutralizing antibody titers) and cellular (as measured by the frequency of PCV2-specific interferon-γ-secreting cells) immune response in the PCV2-viremic piglets after vaccination even in the presence of maternally derived antibodies (MDA). The initial infection of PCV2 in the pigs was not affected by PCV2 vaccination, however the challenging PCV2 was reduced by PCV2 vaccination on PCV2-viremic pigs. The results from this study demonstrate that the PCV2 vaccine used in this study is effective at reducing PCV2 viremia and lymphoid PCV2 DNA, even for PCV2-viremic pigs with passively acquired MDA at the time of vaccination.
本研究旨在评估猪圆环病毒 2 型（PCV2）疫苗对源自自然感染 PCV2 母猪的 PCV2 血症和血清阳性仔猪在产后 PCV2 挑战中的效果。该实验设计旨在模拟商业养猪条件，以评估 PCV2 疫苗对实验性 PCV2 挑战后 PCV2 血症和血清阳性仔猪的反应。PCV2a（或 2b）血症仔猪在 21 日龄时接种 PCV2 疫苗，然后在 49 日龄（接种后 28 天）时接种 PCV2b（或 2a）挑战。PCV2 疫苗在接种后即使存在母源抗体（MDA），也能在 PCV2 血症仔猪中引起高水平的体液（如免疫过氧化物酶单层测定和中和抗体滴度所测量）和细胞（如 PCV2 特异性干扰素-γ分泌细胞的频率所测量）免疫反应。然而，PCV2 疫苗接种并未影响猪的初始 PCV2 感染，但在 PCV2 血症仔猪中，PCV2 疫苗接种可减少挑战性 PCV2。本研究结果表明，本研究中使用的 PCV2 疫苗可有效降低 PCV2 血症和淋巴组织 PCV2 DNA，即使在接种时仔猪具有被动获得的 MDA 也是如此。
