Feng Hua, Blanco Gerardo, Segalés Joaquim, Sibila Marina
Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
Departament de Producció Animal, ETSEA, Universitat de Lleida, 25198 Lleida, Spain.
Vet Microbiol. 2014 Aug 6;172(1-2):92-9. doi: 10.1016/j.vetmic.2014.05.003. Epub 2014 May 13.
The feasibility to eradicate Porcine circovirus type 2 (PCV2) in a conventional PCV2 infected farm by vaccinating both sows and piglets using a commercially subunit vaccine was assessed. Vaccination strategy implied that all sows, boars and gilts of the farm were vaccinated every four months, and all piglets vaccinated and revaccinated with the same vaccine at 4 and 7 weeks of age, respectively. This vaccination strategy was applied during 12 consecutive months. Blood samples from 15 piglets of 4, 8, 12, 16, 20 and 24 weeks of age and 15 sows were taken monthly PRE, DURING and POST mass vaccination strategy. From all the collected sera (n=1796), a representative proportion of them (n=1235, 69%) were analysed (n=1121 from piglets and n=114 from sows). All these samples were tested by PCV2 ELISA and PCV2 PCR (and quantitative-PCR when PCR positive). All tested sows were negative by PCR but seropositive. ELISA mean OD values of sows decreased throughout the study. Percentages of PCV2 PCR positive samples in piglets were 8% (12/150), 0.9% (6/659) and 3.5% (11/312) PRE, DURING and POST application of the mass vaccination program, respectively. ELISA mean OD values of PCV2 seropositive animals progressively decreased until the end of the mass vaccination period, but a clear seroconversion was observed after stopping such strategy. In conclusion, one year period of mass PCV2 vaccination (without implementing further farm management practices or biosafety measures) was not able to clear out PCV2 infection, and the virus became detectable again when vaccination was stopped.
评估了在一个传统的猪圆环病毒2型（PCV2）感染猪场中，使用商业化亚单位疫苗对母猪和仔猪进行免疫接种以根除PCV2的可行性。免疫接种策略为，该猪场所有的母猪、公猪和后备母猪每四个月接种一次疫苗，所有仔猪分别在4周龄和7周龄时接种该疫苗并进行再次接种。此免疫接种策略持续应用了12个月。在大规模免疫接种策略实施前、期间和之后，每月采集15头4、8、12、16、20和24周龄仔猪以及15头母猪的血样。从所有采集的血清（n = 1796）中，选取了具有代表性的一部分（n = 1235，69%）进行分析（仔猪1121份，母猪114份）。所有这些样本均通过PCV2 ELISA和PCV2 PCR检测（PCR阳性时进行定量PCR）。所有检测的母猪PCR结果均为阴性，但血清学检测呈阳性。在整个研究过程中，母猪的ELISA平均OD值下降。在大规模免疫接种计划实施前、期间和之后，仔猪中PCV2 PCR阳性样本的百分比分别为8%（12/150）、0.9%（6/659）和3.5%（11/312）。PCV2血清学阳性动物的ELISA平均OD值在大规模免疫接种期结束前逐渐下降，但在停止该策略后观察到明显的血清转化。总之（在未实施进一步的猪场管理措施或生物安全措施的情况下），为期一年的大规模PCV2免疫接种未能清除PCV2感染，且在停止接种后病毒再次变得可检测到。
