Abstract：
BACKGROUND: Mycoplasma hyopneumoniae (M. hyo) and Porcine Circovirus Type 2 (PCV2) are major pathogens that cause significant health problems in swine worldwide. Maternal derived immunity (MDI) has been suggested as a significant immediate defence factor for newborn piglets and may interfere with piglet\'s vaccination-induced immunity. The study aimed to assess the efficacy of a novel combination vaccine (consisting of PCV2 subunits and inactivated M. hyo strain J), against PCV2 and M. hyo natural infection [Porcilis® PCV M Hyo (MSD Animal Health, Boxmeer, the Netherlands)], in the presence of strong maternally derived PCV2 immunity (antibody titre averaged 11.08 log2), under field conditions. The study was performed according to a controlled, randomized and blinded design in a Greek swine unit with Enzootic Pneumonia (EP) and subclinical PCV2 infection. In total, 600 healthy three-week-old suckling piglets were allocated randomly, either to treatment (vaccinated with the test product) or control group (injected with sterile buffered saline).
RESULTS: Vaccination significantly reduced the severity of lung lesions at slaughter (lesions of cranio-ventral pulmonary consolidation) (P < 0.001). The overall mean lung lesion score (LLS) was 9.6 in the vaccinated group and 12.2 in controls. The level of PCV2 viraemia was significantly reduced in vaccinated pigs. Furthermore, 25 g higher average daily weight gain (ADWG) was observed during the finishing phase (P < 0.001) and 18 g greater ADWG overall (P < 0.001).
CONCLUSIONS: Results of LLS, PCV2 viremia and ADWG support the test product\'s efficacy in the face of strong maternally derived PCV2 immunity.
RESULTS: Vaccination significantly reduced the severity of lung lesions at slaughter (lesions of cranio-ventral pulmonary consolidation) (P < 0.001). The overall mean lung lesion score (LLS) was 9.6 in the vaccinated group and 12.2 in controls. The level of PCV2 viraemia was significantly reduced in vaccinated pigs. Furthermore, 25 g higher average daily weight gain (ADWG) was observed during the finishing phase (P < 0.001) and 18 g greater ADWG overall (P < 0.001).
CONCLUSIONS: Results of LLS, PCV2 viremia and ADWG support the test product\'s efficacy in the face of strong maternally derived PCV2 immunity.
摘要：
背景：猪肺炎支原体（M.hyo）和猪圆环病毒2型（PCV2）是在全球范围内引起猪重大健康问题的主要病原体。母源免疫(MDI)已被认为是新生仔猪的重要即时防御因子,并可能干扰仔猪的疫苗诱导免疫。该研究旨在评估新型联合疫苗（由PCV2亚基和灭活的M.hyo菌株J组成）的功效，针对PCV2和M.hyo自然感染[Porcilis®PCVMHyo(MSD动物健康，Boxmeer,theNetherlands)],在存在强大的母源PCV2免疫（抗体滴度平均11.08log2）的情况下，在现场条件下。这项研究是根据对照进行的，随机和盲法设计在希腊猪单位与内生性肺炎（EP）和亚临床PCV2感染。总的来说,随机分配600只健康的三周龄哺乳仔猪，治疗组(用测试产品接种疫苗)或对照组(注射无菌缓冲盐水)。
结果：接种疫苗可显著降低屠宰时肺部病变的严重程度（颅腹肺实变）（P<0.001）。总体平均肺损伤评分(LLS)在接种组中为9.6,在对照中为12.2。在接种疫苗的猪中PCV2病毒血症的水平显著降低。此外，在整理阶段观察到25g较高的平均日增重(ADWG)(P<0.001),并且总体上观察到18g较高的ADWG(P<0.001)。
结论：LLS的结果，PCV2病毒血症和ADWG支持测试产品在面对强大的母源性PCV2免疫时的功效。
结果：接种疫苗可显著降低屠宰时肺部病变的严重程度（颅腹肺实变）（P<0.001）。总体平均肺损伤评分(LLS)在接种组中为9.6,在对照中为12.2。在接种疫苗的猪中PCV2病毒血症的水平显著降低。此外，在整理阶段观察到25g较高的平均日增重(ADWG)(P<0.001),并且总体上观察到18g较高的ADWG(P<0.001)。
结论：LLS的结果，PCV2病毒血症和ADWG支持测试产品在面对强大的母源性PCV2免疫时的功效。
