Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
Vaccine. 2012 Oct 19;30(47):6671-7. doi: 10.1016/j.vaccine.2012.08.065. Epub 2012 Sep 7.
Inactivated chimeric porcine circovirus (PCV) 1-2 vaccine was initially taken off the market due to concerns that the vaccine virus was not killed and thus further replicated and spread in the pig population. In August 2011, a reformulated inactivated chimeric PCV1-2 vaccine re-entered the market. The efficacy of the reformulated inactivated chimeric PCV1-2 vaccine was evaluated under field conditions for registration as recommended by the Republic of Korea's Animal, Plant & Fisheries Quarantine & Inspection Agency. Three farms were selected based on their history of postweaning multisystemic wasting syndrome (PMWS). On each farm, a total of 50 3-week-old pigs were randomly allocated to one of two treatment groups: (i) vaccinated at 3 weeks of age and (ii) non-vaccinated. Clinical examination indicated that vaccinated animals displayed an improved average daily weight gain (672.2g/day vs. 625g/day; difference of +47.3g/day; P<0.05) and a reduced time to market (177 days vs. 183 days; difference of -6 days; P<0.05). Virological examination indicated that vaccinated animals displayed a reduced PCV2 load in the blood and nasal swabs compared to non-vaccinated animals. Pathological examination indicated that vaccination of pigs against PCV2 effectively reduced the number of PMWS-associated microscopic lesions and the PCV2 load in lymphoid tissues compared to non-vaccinated animals in the 3 herds. Immunological examination indicated that vaccinated animals induced PCV2-specific neutralizing antibodies (NA) and interferon-γ-secreting cells (IFN-γ-SCs). A reduction in the PCV2 load in the blood coincided with the appearance of both PCV2-specific NA and IFN-γ-SCs in the vaccinated animals. The number of CD4(+) cells was decreased in non-vaccinated animals compared to vaccinated animals. The reformulated inactivated chimeric PCV1-2 vaccine seems to be very effective in controlling PCV2 infection based on clinical, virological, pathological, and immunological evaluations under field conditions.
嵌合型猪圆环病毒 1-2 型（PCV1-2）灭活疫苗最初因担心疫苗病毒未被杀死而在猪群中进一步复制和传播而被撤出市场。2011 年 8 月，一种改良的嵌合型 PCV1-2 型灭活疫苗重新进入市场。根据韩国动植物检疫局的建议，在田间条件下对改良的嵌合型 PCV1-2 型灭活疫苗的功效进行了评估，以获得注册。根据其断奶后多系统衰竭综合征（PMWS）的历史，选择了三个农场。在每个农场，将总共 50 头 3 周龄的猪随机分配到以下两个治疗组之一：（i）3 周龄时接种疫苗，（ii）不接种疫苗。临床检查表明，接种疫苗的动物的平均日增重（672.2g/天对 625g/天；差值为+47.3g/天；P<0.05）提高，上市时间缩短（177 天对 183 天；差值为-6 天；P<0.05）。病毒学检查表明，与未接种疫苗的动物相比，接种疫苗的动物血液和鼻拭子中的 PCV2 载量降低。病理检查表明，与未接种疫苗的动物相比，接种疫苗可有效减少 3 个畜群中 PMWS 相关的微观病变和淋巴组织中的 PCV2 载量。免疫检查表明，接种疫苗可诱导猪产生 PCV2 特异性中和抗体（NA）和干扰素-γ分泌细胞（IFN-γ-SC）。接种动物血液中的 PCV2 载量降低与 PCV2 特异性 NA 和 IFN-γ-SC 的出现同时发生。与接种疫苗的动物相比，未接种疫苗的动物的 CD4+细胞数量减少。在田间条件下，基于临床、病毒学、病理学和免疫学评估，改良的嵌合型 PCV1-2 型灭活疫苗似乎对控制 PCV2 感染非常有效。
