导致马立克疫苗免疫失败的原因分析

鸡马立克氏病是鸡的主要传染病之一,鸡马立克病疫苗的预防接种是控制疾病的主要手段,而在其使用过程中经常出现免疫失败的现象,本文系统的阐述了导致马立克疫苗免疫失败的原因并进行分析,为鸡马立克氏疫苗的正确使用提供帮助。     

鸡马立克氏病冷冻疫苗的使用

防制鸡马立克氏病有两类疫苗:一类是鸡马立克氏病弱毒(人工减弱或自然弱毒)疫苗,另一类是火鸡疱疹病毒疫苗。我国于1978年起开始使用火鸡疱疹病毒冻干疫苗,对防制鸡马立克氏病起了一定的作用。但因火鸡疱疹病毒与鸡马立克氏病毒血清型不     

导致马立克疫苗免疫失败的原因分析

鸡马立克氏病是鸡的主要传染病之一,鸡马立克病疫苗的预防接种是控制疾病的主要手段,而在其使用过程中经常出现免疫失败的现象,本文系统的阐述了导致马立克疫苗免疫失败的原因进行分析,为鸡马立克氏疫苗的正确使用提供帮助。     

鸡马立克氏病的诊断方法与防控建议

马立克氏病是鸡最常见的淋巴组织增生性疾病,其特征是形成外周神经及其他器官中的单核细胞浸润和肿瘤。鸡马立克氏病是由疱疹病毒引起的,具有高度传染性,其致病性与其他鸡淋巴肿瘤疾病不同。鸡马立克病的发病率和死亡率高,危害大,常继发鸡病原体,是一种急性传染病,马立克氏病破坏法氏囊、胸腺、脾脏等免疫器官,引起强烈的免疫抑制,并影响各种疫苗的预防效果。病鸡是鸡马立克氏病主要传染源,一旦感染可迅速在鸡群中散播,造成严重的经济损失,因此可以通过实施合理的马立克病诊断和监测方法,积极推广有效的综合防治措施,进一步降低马立克病对鸡造成的经济损失。本文就鸡马立克病给养禽业造成的损失,对鸡马立克病的病因、流行特点、诊断方法以及防控措施等进行了详细论述,以期为防治鸡马立克氏病提供积极有效的方案。     

利安辛与鸡马立克氏病疫苗混合使用的试验观察

为评价利安辛与鸡马立克氏病疫苗联合使用对鸡疫苗免疫效果的影响,在实验室条件下作系统的评估。将不同浓度的利安辛与鸡马立克氏疫苗的稀释液混合后,分不同时间点接种CEF细胞,观察利安辛对鸡马立克氏疫苗蚀斑形成的影响。结果表明利安辛在一定剂量下对鸡马立克氏病疫苗效价没有显著影响。     

马立克氏病双价疫苗的效力

用灭活马立克氏病病毒和火鸡疱疹病毒混合制备了一种双价疫苗。给不分性别的日龄白来航鸡接种,21日龄时用感染强毒马立克氏病病毒的家禽血液攻毒。分别与火鸡疱疹病毒和灭活马立克氏病病毒进行比较,研究了这种疫苗的效力。双价疫苗明显推迟由马立克氏病引起的死亡。按马立克病特异性死亡和病变发生的百分比判定诱发出最高的保护效力。双价疫苗接种鸡各器官的眼观淋巴肿瘤和淋巴组织增生病变的发生率、范围和严重程度均低于其他攻毒鸡。此外,双价疫苗接种鸡的病毒血症水平始终显著低于其他鸡。     

鸡马立克氏病的防疫策略

鸡马立克氏病是鸡最常见的淋巴组织增生性传染病,以外周神经以及性腺、虹膜、各种内脏器官、肌肉和皮肤的单核细胞浸润为特征.在广泛使用疱疹病毒疫苗以后,本病在养鸡业中的危害大大降低.本文介绍了马立克氏病在鸡群的流行特点鸡危害,并阐述了以免疫接种为主防疫策略.     

饲养技术

鸡马立克氏病的防治措施鸡马立克氏病是最常见的一种鸡淋巴组织增生性肿瘤病，以外周神经、性腺、虹膜、各种脏器肌肉和皮肤的单核性细胞浸润为特征。近年来国内各地均有不同程度的发生与流行，对养鸡业危害十分严重。目前由于还没有有效而切实可行的治疗办法，主要靠用疫苗接种来预防和控制鸡马立克氏病。当前国内应用的疫苗有国外进口和国内生产两种，由于疫苗本身的质量和免疫接种方法不当等因素的影响，在实际使用疫苗接种过程中，往往免疫效果不尽一致，因而在接种疫苗后的鸡群仍然发生马立克氏病。如何做好鸡马立克氏病的防治工作?我…     

鸡马立克氏病免疫失败的原因及防制对策

鸡马立克氏病是由疱疹病毒引起的一种淋巴组织增生性疾病,此病的特点是病鸡的外周神经、性腺、虹膜、各种脏器、肌肉和皮肤出现单核细胞浸润,并伴随麻痹和产生内脏肿瘤,它是一种淋巴瘤性质的肿瘤疾病。近年来,许多养鸡场尽管在1日龄雏鸡进行了鸡马立克氏病的免疫接种,但仍然时有发生,并出现了一些新的特点,给养鸡业的生产造成相当大的危害。1免疫失败的原因1.1病毒的早期感染鸡的日龄越小,对马立克氏病毒的敏感性越高。接种疫苗的诱导期一般为7～14d,如果雏鸡在出壳后使用疫苗前或免疫作用未充分建立之前已感染马立克氏病毒,免疫效果就显著…     

三种鸡马立克氏病疫苗的攻毒保护试验比较研究

为比较3种商品化马立克氏病疫苗的免疫效果,本研究将150只1日龄AA+肉鸡随机分为攻毒对照组、乾元浩疫苗组、梅里亚疫苗组、瑞普疫苗组和空白对照组5组,并按厂家说明剂量进行马立克氏病疫苗免疫。8日龄时进行马立克氏病超强毒Md5株攻毒,每天观察各组临床症状,对病死鸡进行剖检和病理组织学观察。根据免疫攻毒后的临床观察、剖检病变和病理切片等综合分析,梅里亚疫苗组的保护指数略高于乾元浩疫苗组和瑞普疫苗组,差异不显著（P > 0.05）,说明不同厂家生产的鸡马立克氏病疫苗对Md5超强毒株的攻击具有相似的保护效果。因此在生产中使用国产马立克氏病疫苗或进口马立克氏病疫苗均能对我国当前流行的马立克氏病有较好的保护效果。     

口蹄疫新型疫苗研究进展

口蹄疫是由口蹄疫病毒感染引起的偶蹄动物共患的急性、热性、接触性传染病,接种疫苗是特异性预防口蹄疫的有效手段,口蹄疫疫苗主要有弱毒疫苗、灭活疫苗及新型疫苗。自20世纪80年代开始,基因工程亚单位疫苗、合成肽疫苗、病毒活载体疫苗、基因缺失疫苗、重组表位疫苗、核酸疫苗等新型疫苗研究日趋活跃,现对各类型疫苗的研究进展作一综述。     

牛传染性鼻气管炎疫苗的研究进展

牛传染性鼻气管炎(infectious bovine rhinotracheitis,IBR)是由牛传染性鼻气管炎病毒(infectious bovine rhinotracheitis virus,IBRV)即牛疱疹病毒1型(BoHV-1)感染所引起的一种高度接触性传染病。该病给我国养牛业带来了巨大的经济损失。由于缺乏有效的治疗性药物,疫苗免疫仍然是防控该病的有效措施。当前,牛传染性鼻气管炎疫苗主要包括灭活疫苗、弱毒疫苗2种常规疫苗和亚单位疫苗、DNA疫苗、IBRV基因缺失疫苗、病毒活载体疫苗4种基因工程疫苗,各种疫苗各有优点。现对上述疫苗的最新研究进展进行综述,以期为IBRV疫苗的研究与开发提供参考。     

日本血吸虫候选疫苗免疫保护力研究进展

血吸虫病是危害严重的寄生虫病之一,其疫苗的研究是血吸虫病防治的一项工作重点也是一大难题。本文综述了日本血吸虫疫苗侯选分子筛选、模拟表位疫苗和多价疫苗的研究现状,并对血吸虫疫苗的深入研究进行了分析。     

抗菌药对马立克氏病活疫苗毒性的作用

用不同剂量的青霉素钾、硫酸链霉素、硫酸卡那霉素、硫酸庆大霉素和恩诺沙星等５种常见抗菌药加入ＨＶＴ冻干菌、ＣＶＩ９８８细胞结合苗和Ｚ４＋ＦＣ１２６双价活疫苗中,作用１ｈ后,分别取样计数,研究其对马立克氏病（ＭＤ）疫苗的毒性作用。结果表明：５种抗菌药加入ＭＤ疫苗稀释液后,ｐＨ值变化较大,ＭＤ疫苗空斑数显著减少,以至使ＭＤ疫苗失效。     

口蹄疫基因疫苗研究进展

口蹄疫是一种危害严重的偶蹄动物传染病 ,研制新型口蹄疫疫苗是防治口蹄疫爆发的有效措施之一。自 1 990年首次出现基因疫苗的研究报道之后 ,基因疫苗已成为疫苗研究领域中的一大热点。文章介绍了近年来国内外在口蹄疫基因疫苗研究方面的新进展 ,包括口蹄疫基因疫苗构成的基本条件、口蹄疫基因疫苗的免疫机理、口蹄疫基因疫苗的不同免疫形式以及免疫佐剂在口蹄疫基因疫苗研究中的应用 ,并对口蹄疫基因疫苗的发展前景进行了讨论     

鱼用疫苗研究进展

鱼用疫苗的种类繁多,除传统疫苗之外,新型疫苗包括合成肽疫苗、DNA疫苗、活载体疫苗、基因缺失疫苗等.一些与鱼用疫苗相关的领域如免疫佐剂、接种方法的研究也逐渐深入.本文对以上研究进展进行了概述,为我国鱼用疫苗的进一步研究和发展提供一些依据.     

DNA vaccines and their applications in veterinary practice: current perspectives

Inoculation of plasmid DNA, encoding an immunogenic protein gene of an infectious agent, stands out as a novel approach for developing new generation vaccines for prevention of infectious diseases of animals. The potential of DNA vaccines to act in presence of maternal antibodies, its stability and cost effectiveness and the non-requirement of cold chain have heightened the prospects. Even though great strides have been made in nucleic acid vaccination, still there are many areas that need further research for its wholesome practical implementation. Major areas of concern are vaccine delivery, designing of suitable vectors and cytotoxic T cell responses. Also, the induction of immune responses by DNA vaccines is inconclusive due to the lack of knowledge regarding the concentration of the protein expressed in vivo. Alternative delivery systems having higher transfection efficiency and the use of cytokines, as immunomodulators, needs to be further explored. Recently, efforts are being made to modulate and prolong the active life of dendritic cells, in order to make antigen presentation a more efficacious one. For combating diseases like acquired immunodeficiency syndrome (AIDS), influenza, malaria and tuberculosis in humans; and foot and mouth disease, Aujesky’s disease, swine fever, rabies, canine distemper and brucellosis in animals, DNA vaccine clinical trials are underway. This review highlights the salient features of DNA vaccines, and measures to enhance their efficacy so as to devise an effective and novel vaccination strategy against animal diseases.     

Concomitant turkey herpesvirus-infectious bursal disease vector vaccine and oil-adjuvanted inactivated Newcastle disease vaccine administration: consequences for vaccine intake and protection

Hatchery vaccination protocols in day-old chicks are designed to provide early priming and protection against several poultry diseases including, but not limited to, Marek's disease (MD), infectious bursal disease (IBD), and Newcastle disease (ND). The constraint of concomitant administration of live MD and IBD vaccines plus ND inactivated oil-adjuvanted vaccines (IOAVs) requires improvements in vaccine technology. Single-needle concomitant subcutaneous (SC) application of IBD/MDV and killed NDV vaccine and the use of viral vectors for expression of immunogenic proteins are a current trend in the industry. The objective of this work was to assess the compatibility of a turkey herpesvirus (HVT)-infectious bursal disease (vHVT-IBD) vector vaccine applied simultaneously with IOAV and to evaluate the consequences for vaccine intake, the need for additional immunizations with the respective vaccines, and protection. Five separate trials were performed using double- and/or single-needle injectors. The levels and persistence of vaccine intake, serologic response, vHVT-IBD virus combination with the MD Rispens strain, and/or live NDV vaccination were also assessed. Histopathology and PCR at injection sites showed adequate vaccine intake detected up to 44 days postvaccination. Serologic evidence of vaccine priming was observed, and all vaccinated groups differed (P < 0.05) from the control at different time points. MD, NDV, and IBD protection results after concomitant double-shot single-needle vaccination were near 85%, 95%, and 100%, respectively. Taken together the results indicate no deleterious effects on the efficacy of the vHVT-IBD vaccine monitored by vaccine intake, serologic and challenge results, and combinations after concomitant live/killed vaccination, suggesting the suitability of its use in hatchery vaccination. All types of injectors used as well as injection techniques, vaccines injected separately or together, gave the same results.     

The efficacy of recombinant fowlpox vaccine protection against Marek's disease: its dependence on chicken line and B haplotype

Earlier studies have shown that the B haplotype has a significant influence on the protective efficacy of vaccines against Marek's disease (MD) and that the level of protection varies dependent on the serotype of MD virus (MDV) used in the vaccine. To determine if the protective glycoprotein gene gB is a basis for this association, we compared recombinant fowlpox virus (rFPV) containing a single gB gene from three serotypes of MDV. The rFPV were used to vaccinate 15.B congenic lines. Nonvaccinated chickens from all three haplotypes had 84%-97% MD after challenge. The rFPV containing gB1 provides better protection than rFPV containing gB2 or gB3 in all three B genotypes. Moreover, the gB proteins were critical, since the B*21/*21 chickens had better protection than chickens with B*13/*13 or B*5/*5 using rFPV with gB1, gB2, or gB3. A newly described combined rFPV/gB1gEgIUL32 + HVT vaccine was analyzed in chickens of lines 15 x 7 (B*2/*15) and N (B*21/*21) challenged with two vv+ strains of MDV. There were line differences in protection by the vaccines and line N had better protection with the rFPV/gB1gEgIUL32 + HVT vaccines (92%-100%) following either MDV challenge, but protection was significantly lower in 15 X 7 chickens (35%) when compared with the vaccine CVI988/Rispens (94%) and 301B1 + HVT (65%). Another experiment used four lines of chickens receiving the new rFPV + HVT vaccine or CVI988/Rispens and challenge with 648A MDV. The CVI 988/Rispens generally provided better protection in lines P and 15 X 7 and in one replicate with line TK. The combined rFPV/gB1gEgIUL32 + HVT vaccines protected line N chickens (90%) better than did CVI988/Rispens (73%). These data indicate that rFPV + HVT vaccines may provide protection against MD that is equivalent to or superior to CVI988/ Rispens in some chicken strains. It is not clear whether the rFPV/gB1gEgIUL32 + HVT vaccine will offer high levels of protection to commercial strains, but this vaccine, when used in line N chickens, may be a useful model to study interactions between vaccines and chicken genotypes and may thereby improve future MD vaccines.     

Compatibility of turkey herpesvirus-infectious bursal disease vector vaccine with Marek's disease rispens vaccine injected into day-old pullets

Mixtures of turkey herpesvirus (HVT) and Rispens poultry vaccines have been used worldwide for over 20 yr, mainly for vaccination of future layers and breeders. With increasing virulence of Marek's disease (MD) virus strains, vaccination strategies are evolving toward the use of vaccines combining HVT and Rispens. A single vaccination either in ovo or at 1 day of age with the HVT + infectious bursal disease (IBD) vector vaccine is efficient against IBD. However, with vaccination programs that include a hatchery administration of the HVT + IBD vaccine, additional protection against very virulent and very virulent-plus MD viruses is needed, especially for layers and breeders. This study looked at the combination of four commercially available Rispens vaccines with the HVT + IBD vector vaccine injected at 1 day of age. MD challenge tests that were superior to 90% in relative score in all the groups vaccinated with both vaccines showed that the mixture of HVT + IBD and Rispens vaccines had no effect on clinical protection against MD, and IBD challenge tests showed that the mixture of HVT + IBD and Rispens vaccines had no effect on clinical protection against IBD, which was equal to 100% protection in all the groups vaccinated with both vaccines.