猪瘟疫苗不同免疫剂量免疫效果对比试验

为探讨不同免疫剂量下猪瘟疫苗的免疫效果,对规模猪场150头仔猪进行免疫对比试验.结果显示,25～30日龄首免1头份、60～65日龄二免1头份即可达到较好免疫效果,25～30日龄首免2头份、60～65日龄二免2头份免疫效果稍优于免疫1头份,二免后仔猪抗体合格率均达了国家规定的70％的标准.     

猪瘟细胞疫苗和猪瘟脾淋疫苗及不同免疫剂量免疫效果的试验

试验选择25日龄左右健康仔猪若干头,经检测选择其中母源抗体1:16以下的健康仔猪80头为试验猪。随机分成A、B、C、D四组,每组20头。组均日龄达30天时分别肌肉注射猪瘟细胞疫苗2头份、4头份和猪瘟脾淋疫苗1头份、2头份,对免疫后的副反应进行观察和对不同时段的抗体进行跟踪检测。结果表明:A、B、C、D四组的群体保护率都较好,其中C组未见免疫副反应,群体保护率维持时间最长。试验证实猪瘟脾淋疫苗对本育种基地猪群免疫效果优于猪瘟细胞疫苗。不论猪瘟细胞疫苗还是猪瘟脾淋疫苗加大免疫剂量均会增大出现免疫副反应的风险。     

猪瘟传代细胞疫苗临床免疫试验效果评价及分析

在非洲猪瘟全国流行的情况下,经典猪瘟的免疫尤为重要。不同公司生产的猪瘟疫苗的免疫效果及免疫副反应不同,为选择优质疫苗,选择两个不同厂家猪瘟传代细胞疫苗,开展断奶猪两次免疫并收集数据,进行免疫效果及免疫副反应的评价。从副反应统计及疫苗效果跟踪可知,B公司猪瘟产品效果明显好于A公司产品。之后将B公司猪瘟疫苗产品应用在规模猪场进行临床效果跟踪,结果表明猪瘟抗体水平明显提升,且临床仔猪猪瘟抗体较高,可为猪瘟疫苗评价及防控提供参考。     

不同猪瘟疫苗及不同剂量免疫效果

为了掌握仔猪免疫猪瘟细胞苗和脾淋苗的抗体效果,设立一个试验场,选择饲养环境相同的同群的母猪所产的仔猪,分别进行猪瘟细胞苗、猪瘟脾淋苗及不同免疫剂量试验。免疫抗体的监测结果表明,猪瘟抗体效价均在25以上,达到合格标准。对免疫猪瘟细胞苗或脾淋苗后的抗体监测情况对比分析表明,两种疫苗无差异,说明两种疫苗均可推广应用。猪瘟细胞苗或脾淋苗免疫不同剂量,免疫效果无差异;首免和二免两次选择两种疫苗免疫和选择一种相同疫苗免疫,免疫效果无差异。     

不同厂家猪瘟疫苗免疫效果比对试验

为准确掌握汉中市规模猪场使用量最大的两种猪瘟疫苗在实际应用中的免疫效果,在规模猪场选择4窝体质健康、体重接近的仔猪,随机分成4组,每组10头,分别接种猪瘟脾淋苗和细胞苗,采用IHA方法检测免疫接种前后抗体效价。结果显示,用标准剂量免疫后,2种疫苗都不能对猪群产生保护作用,用2头份剂量在仔猪30日龄首免,首免后28d加强免疫,2种疫苗都能对猪群产生很好的保护作用,能满足预防猪瘟疫病的需要,同时猪瘟脾淋苗免疫后刺激机体产生抗体的速度快,可用于紧急免疫接种。广大养殖户可以根据实际情况,科学合理选择使用猪瘟疫苗。     

不同来源猪瘟疫苗的免疫效果试验

为比较不同厂家生产的猪瘟疫苗免疫效果,选择苍南县条件良好的规模猪场,选用江西、山东和青岛等3家厂家生产的猪瘟细胞苗和脾淋苗进行免疫效果试验。结果表明,政府采购供应的猪瘟疫苗质量可靠,免疫效果较好;对部分特定猪场而言,掌握母源抗体的变化规律意义重大,临床发现的部分猪瘟免疫抗体水平较低,则可能与较强的母源抗体干扰有关。     

不同猪瘟疫苗对仔猪免疫效果对比试验

试验随机选择了5窝断奶仔猪,每窝6头,共30头。随机分成3个组,每组10头,其中试验1组接种猪瘟兔化弱毒细胞苗(猪瘟活疫苗Ⅱ系),试验2组接种猪瘟组织苗(猪瘟活疫苗Ⅲ系),试验3组接种猪瘟脾淋苗(猪瘟活疫苗Ⅰ系),每头仔猪均接种剂量2头份。在免疫15d后,分别采血、分离血清、检测猪瘟抗体水平。检测结果,试验1组、试验2组、试验3组的平均抗体水平分别为1∶56、1∶60、1∶194。统计分析表明:猪瘟脾淋苗免疫效果最好(P<0.01),而猪瘟细胞苗和组织苗两者抗体水平差异不显着(P>0.05),但从总体上看3种疫苗使用2头份剂量免疫15d后都能使仔猪获得良好的保护力。     

辽宁地区不同猪瘟疫苗免疫效果比较试验

在辽宁选取3个使用不同厂家猪瘟疫苗的生猪养殖场,对受试场的猪瘟疫苗免疫效果进行评估,比较疫苗免疫效果。结果表明,在辽宁地区使用的强制免疫疫苗和杭州某公司生产的猪瘟疫苗,免疫效果较好,其抗体生成率较高,可在辽宁地区生猪饲养场推广应用,以确保辽宁地区猪瘟的综合防控效果。     

浅谈提高猪瘟疫苗的免疫效果

猪瘟是猪的一种高度传染性致死性传染病,其特征,急性的主要是高热稽留和小血管壁变性引起的出血、梗塞和坏死等变化。而慢性的,则以纤维素性、坏死性肠炎为特征。近几年出现的非典型猪瘟,     

猪瘟疫苗研究进展及我国传统疫苗的研究现状

简要介绍了国内外传统猪瘟疫苗和新型猪瘟疫苗的研究进展,着重对我国猪瘟传统疫苗的特点、生产工艺、生产和应用中的问题进行了概述,并对猪瘟疫苗研究做了展望.     

应用定量RT-PCR对猪瘟兔化弱毒疫苗的质量评价研究

为进一步验证猪瘟兔化弱毒(HCLV)疫苗荧光定量RT-PCR(qRT-PCR)与兔体定型热试验之间存在正相关性,本研究利用qRT-PCR方法对278批次HCLV疫苗进行检测,分别检测其疫苗含量及牛病毒性腹泻病毒(BVDV)污染情况。结果表明,278批次猪瘟疫苗中有66批(24%)疫苗含量达不到规程标准,有42批(15%)疫苗存在BVDV污染;从所检疫苗中抽取6份qRT-PCR检测HCLV含量较低的疫苗,采用兔体定型热试验进行验证,两种方法结果吻合,表明qRT-PCR方法可以作为评价猪瘟疫苗质量的一种备选方法。     

A promising multiple-epitope recombinant vaccine against classical swine fever virus

Classical swine fever (CSF) is a highly contagious and often fatal disease of swine. It is caused by classical swine fever virus (CSFV), one of the members of the genus Pestivirus of the Flaviviridae family. The development of a safe and effective vaccine against the CSF is critical to pandemic control, this article shows a tandem-repeat multiple-epitope recombinant vaccine can protect pigs from CSFV challenge. That was composed as following: two copies each of glycoprotein E2 residues 693–707, 241–276 and 770–781, and two copies amino acid residues 1446–1460 of the non-structural protein NS2-3. In the challenge test, all of the swine vaccinated with Chinese vaccine strain (C-strain) were fully protected from a challenge with CSFV. However, after three successive vaccinations with the multiple-epitope recombinant vaccine, three out of five pigs were protected from challenge with CSFV (in terms of both clinical signs and viremia). These results demonstrate that multiple-epitope recombinant vaccine which carrying the major CSFV epitopes can induce a high level of epitope-specific antibodies and exhibit a protective capability that parallels induced by C-strain to a certain extent.     

Efficacy of the classical swine fever (CSF) marker vaccine Porcilis Pesti in pregnant sows

The efficacy of the classical swine fever (CSF) subunit marker vaccine Porcilis Pesti based on baculovirus expressed envelope glycoprotein E2 of CSF virus (CSFV) was evaluated in pregnant sows. Ten gilts were vaccinated with one dose of marker vaccine, followed by a second dose 4 weeks later. Four gilts remained unvaccinated and received a placebo at the same times. Thirty-three days after the second vaccination all animals were artificially inseminated. Neither local or systemic reactions nor an increase of body temperature were observed after vaccinations. All gilts showed a normal course of pregnancy. Thirty-five days after first vaccination all animals developed E2 specific neutralising antibodies with titres in the range of 5.0 and 7.5 log(2). No antibodies to CSFV-E(rns) were found in ELISA.On day 65 of gestation (126 days after the first immunisation) all sows were infected intranasally using 2ml (10(6.6) TCID(50)/ml) of the low virulent CSFV strain "Glentorf". After challenge in two of the unvaccinated control sows a slight transient increase of body temperature was observed, whereas leukopenia was demonstrated in all control animals. In addition all controls became viraemic. Vaccinations with the CSFV subunit vaccine protected the animals from clinical symptoms of CSF. In two sows a moderate decrease of leukocyte counts was detected on day 5 post infection. In contrast to the unvaccinated control sows in none of the vaccinated animals virus was isolated from the nasal swabs or the blood.Approximately 40 days after challenge all sows were killed and necropsy was done. The sows and their offspring were examined for the presence of CSFV in blood, bone marrow and different organs. No virus was found in any of the sows. In contrast, in all litters of the control sows CSFV was found in the blood as well as in the organ samples. Nine out of 10 litters of the vaccinated sows were protected from CSFV infection. Blood samples, lymphatic organs and bone marrow of these animals were all virologically negative. When sera were tested for CSFV-antibodies all sows had developed E(rns)-specific antibodies but no CSFV-specific antibodies were found in any of the progeny.It was concluded that vaccination with CSF subunit marker vaccine Porcilis((R)) Pesti protected 90% of the litters from viral infection when sows were challenged mid-gestation using the CSFV-strain "Glentorf".     

Oral immunisation against classical swine fever (CSF): onset and duration of immunity

A recently developed competitive PCR for ovine herpesvirus 2 (OvHV-2) was used to examine the levels of viral DNA in nasal secretions and peripheral blood leukocytes (PBL) of lambs and adult sheep. Viral DNA first appeared in the PBL of most lambs after about 3 months of age and the levels remained relatively constant thereafter. In most of the lambs (83%, n=12), viral DNA was undetectable by PCR in nasal secretions prior to 5 months of age. A dramatic rise of OvHV-2 DNA levels in the nasal secretions occurred starting at 5-6 months of age, which peaked at approximately 7 months. The highest level recorded in lamb nasal secretions was 7.5x10(8)copies/2microg DNA which were 75,000-100,000-fold higher than the levels in PBL of the same lambs. In adult sheep (n=10), the viral DNA levels in both PBL and nasal secretions were relatively stable over the 13-month period of the study, which included a lambing season. The data strongly suggest that neonatal lambs are not an important source for the transmission of OvHV-2 to clinically susceptible species, and that the nasal cavity is an important portal for shedding of infectious OvHV-2 in sheep. Furthermore, this study failed to identify a seasonal pattern in levels of viral DNA in nasal secretions or PBL of adult sheep that would provide a basis for the traditionally held belief that clinical cases of malignant catarrhal fever are significantly associated with lambing ewes.     

三个厂家猪瘟活疫苗免疫效果比较试验

在同一条件下对3个厂家生产的猪瘟细胞源活疫苗进行了免疫效果评价试验,并与猪瘟传代细胞苗免疫效果进行比较。结果发现3个厂家生产的猪瘟细胞源活疫苗存在一定差异,2个厂家的免疫效果较好,1个厂家的免疫效果较差。猪瘟传代细胞苗免疫效果优于猪瘟细胞源活疫苗,猪瘟传代细胞苗免疫1次,抗体合格率高,持续时间长,猪瘟细胞源活疫苗要免疫两次才能获得比较好的效果。同时,我们发现高致病性猪蓝耳病活疫苗（JXA1-R株）对猪瘟抗体产生有一定影响。     

猪瘟疫苗中牛病毒性腹泻病毒2型的检测

为对上海某猪场送检的一份猪瘟疫苗进行牛病毒性腹泻病毒(BVDV)检测,本研究将猪瘟疫苗样品接种于MDBK细胞,盲传15代后仍无致细胞病变效应,但间接免疫荧光试验表明接种该疫苗后的MDBK细胞能够被单克隆抗体BZ-53(BVDV-2)识别。采用BVDV-1和BVDV-2的5’-UTR的通用检测引物和针对BVDV E2的引物,对样品RNA进行RT-PCR检测,结果显示,样品能够扩增出约288 bp的BVDV特异性片段;此外,5’-UTR和E2基因片段的测序分析结果表明分离株属于BVDV-2,并且其E2基因与牛源XJ-04株(BVDV-2)的E2基因同源性最高(92.3%),而与猪源ZM-95株(BVDV-1)的E2基因同源性较低(64.5%)。由此证明,该猪瘟疫苗中的确污染有一株BVDV-2株。     

Yeast-expressed classical swine fever virus glycoprotein E2 induces a protective immune response

Classical swine fever (CSF) is an economically important swine disease worldwide. The glycoprotein E2 of classical swine fever virus (CSFV) is a viral antigen that can induce a protective immune response against CSF. A recombinant E2 protein was constructed using the yeast Pichia pastoris expression system and evaluated for its vaccine efficacy. The yeast-expressed E2 (yE2) was shown to have N-linked glycosylation and to form homodimer molecules. Four 6-week-old specified-pathogen-free (SPF) piglets were intramuscularly immunized with yE2 twice at 3-week intervals. All yE2-vaccinated pigs could mount an anamnestic response after booster vaccination with neutralizing antibody titers ranging from 1:96 to 1:768. Neutralizing antibody titers at 10 weeks post booster vaccination ranged from 1:16 to 1:64. At this time, the pigs were subjected to challenge infection with a dose of 1 × 10⁵ TCID₅₀ (50% tissue culture infective dose) virulent CSFV strain. At 1 week post challenge infection, all of the yE2-immunized pigs were alive and without symptoms or signs of CSF. Neutralizing antibody titers at this time ranged from 1:4,800 to 1:12,800 and even to 1:51,200 one week later. In contrast, the control pigs continuously exhibited signs of CSF and had to be euthanized because of severe clinical symptoms at 6 days post challenge infection. All of the yE2-vaccinated pigs were E^rns antibody negative and had seroconverted against E^rns by post challenge day 11, suggesting that yE2 is a potential DIVA (differentiating infected from vaccinated animals) vaccine. The yeast-expressed E2 protein retains correct immunogenicity and is able to induce a protective immune response against CSFV infection.     

Comparison of antibody values in sera of pigs vaccinated with a subunit or an attenuated vaccine against classical swine fever

Ten pigs, aged 85 days, were vaccinated with a subunit vaccine containing 32 g of classical swine fever virus glycoprotein E2 (gp E2) (group 1), and a further 10 pigs were vaccinated with a C strain vaccine (10^4±0.15 TCID₅₀/ml), produced by amplification in minipig kidney (MPK) cell culture (group 2). Nine non-vaccinated pigs served as a control group (group 3). Serum samples were collected before (day 0) and at 4, 10, 21 and 28 days after vaccination and were analysed by two commercially available enzyme immunoassays and by a neutralizing peroxidase-linked assay (NPLA). At the same times, peripheral blood was taken for determining the total leukocyte count and the body temperature was taken daily. Antibodies were not detected in serum samples collected before vaccination (day 0), and no side-effects that could be connected with vaccination were observed during the trial. Ten days after vaccination 6/10 pigs vaccinated with the subunit vaccine were seropositive. On days 21 and 28, the ratios of serologically positive to vaccinated pigs were 9/10 and 10/10, respectively. Four of the ten pigs that were vaccinated with the C strain vaccine were positive on day 21 and 9/10 on day 28. However, the results of the NPLA showed that only 4/10 pigs had an antibody titre >1:32 at the end of the trial in both the vaccinated groups, even though the subunit vaccine initiated an earlier and higher level of neutralizing antibodies than the vaccine produced from the C strain. Challenge was performed 28 days after vaccination on four randomly selected pigs from both vaccinated groups. The pigs survived the challenge without showing any clinical signs of classical swine fever (CSF), while two nonvaccinated control pigs died on the 10th and 12th days after infection.     

猪瘟病毒-猪圆环病毒2型疫苗联合免疫效果的评价

为建立一种既有效又简便的猪瘟和猪圆环病毒病疫苗联合免疫方法,通过细胞感染试验和动物免疫试验,评价了猪圆环病毒2型(PCV2)灭活疫苗和猪瘟病毒(CSFV)冻干活疫苗联合免疫的可行性.通过细胞感染试验证明了PCV2灭活疫苗稀释CSFV冻干活疫苗不影响CSFV疫苗的病毒活性;将PCV2灭活疫苗稀释的CSFV冻干活疫苗免疫试...