猪圆环病毒2型灭活苗免疫试验

猪圆环病毒2型(Porcine circovirus type 2,PCV2)由于常与其它病原混和感染,给养猪业造成巨大的经济损失。本试验用圆环病毒2型灭活苗免疫20日龄仔猪,观察免疫后猪体内抗体消长规律及其对猪只生长的影响。     

猪圆环病毒2型灭活苗的免疫效果

20日龄的仔猪免疫猪圆环病毒2型灭活疫苗,使用ORF2－ELISA方法监测免疫前后的抗体水平,免疫前、免疫2周、免疫3周、免疫4周采集血清,检测结果可以看出,猪群的PCV－2抗体阳性率提高,免疫后4周抗体滴度达到较高水平;免疫组日增重、存活率、净增重均比对照组提高,而且饲料利用率高,药物治疗费由5．67元降低到4．95...     

猪圆环病毒2型灭活疫苗佐剂选择

用水包油佐剂Merckinade SDA 25、HS1010和双向佐剂Montanide ISA 206三种不同佐剂分别制成猪圆环病毒2型灭活疫苗,对三种疫苗的稳定性、黏度、免疫仔猪后的安全性及效力进行了比较。试验结果表明,以3 000 r/min离心15 min,三种疫苗均无水析出;三种疫苗的黏度均低于200 cP;三种疫苗按2.0 mL/头的剂量接种21日龄健康易感猪,试验猪体温、采食、饮水、精神状况均正常,均无不良临床反应,剖检后各脏器均无病理变化;加强免疫后21d,各组试验猪采血,检测猪圆环病毒2型抗体效价,结果表明,佐剂MontanideISA206相较MerckinadeSDA25可诱导更高水平抗体效价。攻毒试验结果表明免疫组可以得到100%的保护。根据以上试验结果,确定猪圆环病毒2型灭活疫苗使用Montanide ISA 206。     

猪圆环病毒2型灭活疫苗免疫试验

采用勃林格殷格翰动物保健公司生产的猪圆环病毒2型杆状病毒载体灭活疫苗,在光明农牧科技有限公司3个畜牧场分别进行免疫核心试验。结果显示,相比对照组,实验组猪成活率、日增重、整齐度等都有较大的改善,投入产出经济效益较好。     

猪圆环病毒Ⅱ型灭活疫苗免疫试验报告

猪圆环病毒病是近年来新发现的猪传染病之一,其病原是Ⅱ型猪圆环病毒(PCV-Ⅱ),以5~12周龄的猪发病率较高,临床主要表现为生长迟缓、进行性消瘦、呼吸困难、贫血、黄疸和腹泻等,急性暴发猪群的死亡率可达10%,个别情况可高达50%。此外该病与猪的多种疾病综合征有关,特别是断奶仔猪多系统衰竭综合征(PMWS)和猪皮炎及肾坏死综合征(PDNS)。PCV-Ⅱ能侵害猪体免疫系统,导致猪体的免疫抑制及抵抗力下降,干扰和破坏猪对其它疫病免疫抗体的产生和维持,从而继发或并发其它疾病,已成为危害养猪业的主要疾病之一。     

猪圆环病毒2型灭活疫苗安全性及免疫效力的评价

为了对制备的猪圆环病毒2型(porcine circovirus type 2,PCV2)灭活疫苗进行安全性及免疫效力的评价,本试验将3批次猪圆环病毒2型灭活疫苗以2倍剂量接种PCV2阴性仔猪后,进行了安全性分析抗体检测和攻毒试验。结果显示：3批次疫苗以2倍剂量接种仔猪后,仔猪均无异常临床反应,可达到1∶1600以上,而攻毒对照组及空白对照组仔猪的抗体水平均在1∶400以下;攻毒后免疫组可以达到100%保护,攻毒对照组出现100%发病。结果表明,所制备的猪圆环病毒2型灭活疫苗对仔猪不仅安全性好,而且可以为仔猪提供有效的保护,为疫苗推广奠定了重要基础。     

猪圆环病毒2型灭活疫苗最小免疫保护剂量研究

猪圆环病毒2型(PCV2)是引起断奶仔猪多系统衰竭综合征(PMWS)的主要病原,疫苗是防制该病的主要手段.为研究PCV2灭活疫苗的免疫效果,本研究将PCV2 SH株灭活,用生理盐水稀释成5×105.0TCID50/mL(高剂量)、2.5×1050 TCID50/mL(中等剂量)、1.25×105.0 TCID50/mL(低剂量)、6.3×104.0 TCID50/mL(超低剂量)4种剂量,与等量白油佐剂乳化后,通过断乳仔猪的免疫攻毒试验观察该灭活疫苗的免疫特性.结果表明,PCV2疫苗抗原含量大于1.25×105.0 TCID50/mL时免疫仔猪后均可以产生特异性抗体,能够明显减轻攻毒后仔猪的临床症状、缓解组织病变、降低病毒血症,对免疫猪有一定的保护效果,可以作为预防PCV2感染的疫苗使用.本研究为研制商品化的PCV2灭活疫苗提供实验依据.     

猪圆环病毒2型灭活疫苗（ZJ/C 株）免疫效果研究

为研究猪圆环病毒2型灭活疫苗（ZJ/C株）在规模猪场的临床使用效果,选取300头14日龄仔猪,平均分为2组,免疫组于14日龄每头肌肉注射圆环病毒2型灭活苗2 mL,对照组每头注射生理盐水2 mL,于免疫前后不同时间点采集7次血样检测各阶段圆环病毒2型抗体,并记录2组在保育及肥育阶段的生长指标。结果显示,免疫后第7天,免疫组抗体阳性率明显升高,免疫后第14天免疫组抗体阳性率已达97%。与对照组相比,免疫组猪在保育阶段日增重提高16 g、料重比降低0.08、成活率提高5.4个百分点;在肥育阶段,日增重提高32 g、料重比降低0.07、呼吸道病发病率下降16.5个百分点、成活率提高3.7个百分点。结果表明,试验猪免疫猪圆环病毒2型灭活疫苗（ZJ/C株）可预防圆环病毒对猪体的危害,提高猪群整体健康度及成活率、饲料转化率和平均日增重。     

猪圆环病毒2型灭活疫苗免疫佐剂的比较试验

以猪圆环病毒2型(PCV2)遗传标记毒株为毒种,经细胞培养传代,优化了病毒增殖条件,获得较高滴度的病毒培养物用于PCV2灭活疫苗的研制。为了比较不同免疫佐剂的效果,本试验对国产矿物质白油和铝胶两种佐剂以及赛比克公司提供的MONTANIDETMISA206、ISA15VG、IMS1315VG3种佐剂配制的灭活疫苗进行了猪体免疫试验。通过临床观察、血清抗体效价测定,确认ISA15VG佐剂配制的疫苗在增强免疫效果方面优于其它佐剂。按5种佐剂免疫效果排序为ISA15VG、IMS1315VG、铝胶、ISA206、国产白油。ISA15VG佐剂属于水包油剂型,可刺激接种动物产生快速免疫应答反应,抗体产生效价高、持续时间长,有可能成为新型PCV2灭活疫苗佐剂的候选。     

猪圆环病毒2型抗体跟踪检测和灭活疫苗免疫效果观察

用Rnls-dCap猪圆环病毒2型抗体酶联免疫检测试剂盒检测杜大长商品仔猪血样143份,其中断奶仔猪血样阳性率58.33%（14/24）、保育仔猪为36.17%（17/47）、育成猪为70.83%（34/48）、育肥猪为91.67%（22/24）。其中10周龄时抗体阳性率最低为33.33%,至14周龄抗体阳性率已升到5...     

Comparative analyses of humoral and cell-mediated immune responses upon vaccination with different commercially available single-dose porcine circovirus type 2 vaccines

The objective of this study was to compare the induction of humoral and cell-mediated immune responses by four commercially available single-dose porcine circovirus type 2 (PCV-2) vaccines. A total of 50 3-week-old piglets were assigned to five groups (10 pigs per group). Four commercial PCV-2 vaccines were administered according to the manufacturer's instructions and the piglets were observed for 154 days post vaccination (dpv). Inactivated chimeric PCV-1-2 vaccines induced higher levels of PCV-2-specific neutralizing antibodies (NA) and interferon-γ-secreting cells (IFN-γ-SC) in pigs than did the other three commercial PCV-2 vaccines. The proportions of CD4⁺ cells were significantly higher in animals vaccinated with inactivated chimeric PCV-1-2 and PCV-2 vaccines than in animals vaccinated with the two subunit vaccines. To our knowledge, this is the first comparison of humoral and cell-mediated immunity induced by four commercial single-dose PCV-2 vaccines under the same conditions. The results of this study demonstrated quantitative differences in the induction of humoral and cell-mediated immunity following vaccination.     

猪圆环病毒2型灭活疫苗效力检验中参考疫苗的应用

制备了4批不同抗原含量的猪圆环病毒2型（PCV2）灭活疫苗,灭活前PCV2病毒含量分别为107.0、106.5、105.5和104.5TCID50/mL。对此4批PCV2灭活疫苗,利用本实验室建立的小白鼠效力检验标准进行效力检验,即以PCV2参考疫苗作为对照品,测定待检疫苗免疫小白鼠后血清中PCV2抗体效价的高低来判定疫苗效力。3次重复检测结果都显示灭活前病毒含量为107.0、106.5和105.5TCID50/mL批次的疫苗合格,而灭活前病毒含量为104.5TCID50/mL批次的疫苗不合格,这与猪体内的效力检验结果一致,表明建立的针对猪圆环病毒2型灭活疫苗的小白鼠效力检验方法具有良好的准确性和重复性。     

猪GM-CSF基因对猪圆环病毒2型DNA疫苗诱导仔猪免疫反应的调节作用

粒细胞-巨噬细胞集落刺激因子（GM-CSF）能够诱导树突状细胞的成熟和存活，并提高其抗原递呈功能，是非常有潜力的分子佐剂之一。为了探讨猪GM-CSF对猪圆环病毒2型（PCV2）DNA疫苗诱导免疫反应的调节作用，本研究将表达猪GM-CSF和PCV2衣壳蛋白的重组质粒混合物（pcDNA3．1-gm-csf和pcDNA3．1-orf2）及在同一载体上表达PCV2衣壳蛋白与猪GM-CSF的双表达重组质粒（pIRES-orf2／gm-csf），分别接种于7日龄健康仔猪，共肌肉注射3次，每次间隔2周。结果表明猪GM-CSF基因能够明显增强PCV2DNA疫苗诱导的特异性体液免疫反应，提高外周血淋巴细胞（PBLC）对ConA刺激的增殖活性，增强NK细胞的杀伤功能，影响细胞因子IL-12、IFN-γ、IL-4和IL-10的表达水平。但GM-CSF基因单独表达和与PCV2衣壳蛋白基因在同一载体上表达，对上述4个细胞因子表达的影响有一定差异。     

猪圆环病毒2型感染对伪狂犬疫苗免疫应答的影响

为明确PCV2感染对伪狂犬(PR)疫苗免疫应答的影响,本研究采用阻断ELISA方法对单独接种猪PR疫苗组(A组)及PCV2人工感染3周后接种猪PR疫苗组(PA组)不同时相血清中的猪PR病毒gB抗体进行检测;同时对不同时相前腔静脉血进行CD4+/CD8+流式细胞术及血常规分析。结果表明,在PCV2感染后2周至5周间,A组白细胞含量均高于PA组,随后PA组白细胞恢复至与A组略高的正常水平;在整个实验中,除接种猪PR疫苗后1周(WPI)和9周(WPI)外的所有时相PA组的淋巴细胞含量均略高于A组;PCV2感染后可使记忆/激活Th细胞数量略有升高,幼稚型Th细胞含量的下降;PCV2感染后2周～7周PA组Tc细胞均高于A组,在9WPIPA组Tc细胞数量显著下降(p0.05);除9WPI外,A组的S/N值均低于PA组。结果表明,PCV2感染看降低机体产生针对PRVgB特异性抗体水平,而且在一定程度上降低了幼稚型Th细胞及Tc细胞含量。     

Efficacy of bivalent vaccines of porcine circovirus type 2 and Mycoplasma hyopneumoniae in specific pathogen-free pigs challenged with porcine circovirus type 2d

BackgroundPorcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (MHP) are economically significant pathogens in the pig industry. The use of combined vaccines against PCV2 and MHP is one of the most effective ways of protecting pigs from both diseases, and it has become a part of general management.ObjectivesThis study evaluated the efficacy of two new bivalent vaccines of PCV2 and MHP (Myco-X and Myco-XD) in SPF pigs. Myco-X and Myco-XD are a combined vaccine of MHP with PCV2b and PCV2d, respectively.MethodsSixteen pigs were divided into four groups: Myco-X-vaccinated challenged, Myco-XD-vaccinated challenged, unvaccinated challenged, and unvaccinated unchallenged. Two milliliters of Myco-X were administered intramuscularly, and 0.5 mL of Myco-XD was injected intradermally at 3 wk of age. The pigs were challenged with virulent PCV2d via the intramuscular and intranasal route 4 wk post-vaccination.ResultsAll vaccinated pigs showed effective reduction of the clinical signs, the PCV2d load in the blood and nasal swab samples, as well as lung and lymphoid tissue lesions in the challenge test. Compared to unvaccinated challenged animals, the vaccinated challenged animals showed significantly higher (p < 0.05) levels of anti-PCV2 IgG, PCV2d-specific interferon-γ (IFN-γ), and anti-MHP IgG.ConclusionsBased on clinical, microbiological, serological, and pathological assessments, this study confirmed that both combined vaccines could protect pigs against PCV2 infection caused by PCV2d. On the other hand, further research on the efficacy evaluation of these new vaccines against the MHP challenge and PCV2d/MHP co-challenge is needed.     

Efficacy of single dose of an inactivated porcine circovirus type 2 (PCV2) whole-virus vaccine with oil adjuvant in piglets

Background

Post-weaning multisystemic wasting syndrome (PMWS) associated with PCV2 is one of the most costly diseases currently faced by the swine industry. The development of effective vaccines against PCV2 infection has been accepted as an important strategy in the prophylaxis of PMWS.

Methods

In the present study, a PK-15 cell-adapted formalin-inactivated prototype vaccine candidate was prepared using a strain of PCV2 from China. Inactivation of the virus was accomplished using a standard formalin inactivation protocol. The protective properties of the inactivated PCV2 vaccine were evaluated in piglets. Ten 28-day-old pigs were randomly assigned to two groups, each with five. Group 1 was vaccinated intramuscularly with the inactivated virus preparation; Group 2 received sterile PBS as a placebo. By 28 days post-vaccination (DPV), Groups 1 and 2 were challenged intranasally and intramuscularly with 5 × 10⁷ TCID₅₀ of a virulent PCV2 isolate.

Results

The vaccinated pigs seroconverted to PCV2 and had high levels of serum antibodies to PCV2 at 28 days after vaccination, whereas the control pigs remained seronegative. No significant signs of clinical disease were recorded following the challenge with PCV2, but moderate amounts of PCV2 antigen were detected in most lymphoid organs of the control pigs. PCV2 was detected in two out of the five vaccinated pigs. Furthermore, pathological lesions and viremia were milder in the vaccinated group.

Conclusions

The obtained results indicate that the inactivated PCV2 virus vaccine with an oil adjuvant induce an immunological response in pigs that appears to provide protection from infection with PCV2. The vaccine, therefore, may have the potential to serve as a vaccine aimed to protect pigs from developing PMWS.     

First report of porcine circovirus type 2 infections in Cuba

To obtain information about the porcine circovirus type 2 (PCV2) infection status of pigs in Cuba and the probable association of PCV2 with other porcine viruses, tissue samples collected from ill pigs were evaluated using polymerase chain reaction (PCR). The PCR analysis showed that 67.7% of the samples (23/34) from seven swine herds of six different geographic regions were detected to be positive for PCV2. Ten of the 23 PCV2 positive samples (43.5%) shown a concurrent infection with porcine parvovirus (PPV) and 17 of 23 PCV2 positive samples (73.9%) exhibited a concomitant infection with classical swine fever virus (CSFV). This study is the first report of PCV2 infecting pigs with different clinical conditions in Cuban swine herds and provides evidence of PCV2 co-infection with PPV and CSFV in the field.     

猪圆环病毒2型研究进展

猪圆环病毒2型（PCV2）已成为家猪和野猪常见的一种病毒病,由其引起的疾病称为猪圆环病毒相关疾病（PCVAD）,自猪圆环病毒相关疾病（PCVAD）暴发以来,已成为近年来阻碍养猪业发展的重要传染病。为了进一步了解该病,以便更好地预防和控制该病,本文从病原学、流行病学、致病机理、临床症状、防控措施等方面进行了综述。     

规模化猪场猪圆环病毒2型感染的实验室诊断

为了确诊贵州省某规模化猪场保育仔猪异常死亡原因,从怀孕母猪、产房母猪、后备母猪、种公猪、哺乳仔猪、保育仔猪6个猪群采集90份血清样本采用ELISA方法分别进行血清抗体检测,并对采集的90份血清样本和1份病死猪淋巴结组织采用荧光PCR方法进行病原学检测。结果:6个猪群综合的猪瘟病毒、猪蓝耳病病毒、伪狂犬病病毒g B蛋白、伪狂犬病病毒g E蛋白血清抗体阳性率分别为87.78%、70.00%、88.89%、4.44%;猪瘟病毒、猪蓝耳病病毒、伪狂犬病病毒病原核酸检测显示阴性,猪圆环病毒2型病原核酸检测淋巴结组织样本显示阳性。试验结果表明,引起该猪场保育仔猪死亡的原因为猪圆环病毒2型感染。同时,怀孕母猪群出现了伪狂犬病病毒g E蛋白抗体阳性,提示怀孕母猪群可能存在猪伪狂犬病野毒感染。