鸡传染性法氏囊病新型疫苗的研究进展

鸡传染性法氏囊病(IBD)是由鸡传染性法氏囊病病毒(IBDV)引起的雏鸡的一种高度接触性传染病,自1962年报道以来,世界上主要养禽国家和地区均有流行,给养禽业带来严重经济损失。目前,IBD防控的主要方法是采用疫苗接种,使易感雏鸡获得主动或被动免疫保护,因此疫苗的质量对临床上IBD的防控起着至关重要的作用。虽然各国均有较好的商品化疫苗,但随着IBDV毒株的不断变异,商品化疫苗的抗原性与流行毒株不能完全匹配,临床上免疫失败时有发生,因此迫切需要研发与临床流行毒株相匹配的新型疫苗用于IBD的防控。对近期IBD的基因缺失苗、亚单位疫苗、DNA疫苗以及活载体疫苗等新型疫苗的研究进展进行概述,以此为IBD新型疫苗的研究提供参考。     

HVT＋IBD二联疫苗对黄羽肉鸡传染性法氏囊病的免疫保护效果

传染性法氏囊病超强毒株的存在导致传染性法氏囊病时有发生。为了预防超强毒株引起的传染性法氏囊病,在黄羽肉鸡中多使用中强毒力的传染性法氏囊病活疫苗,但这一类疫苗会影响雏鸡免疫系统的发育,导致免疫抑制现象。HVT＋IBD二联疫苗（威力克）是梅里亚公司生产的一种新型疫苗,是将传染性法氏囊病病毒的主要免疫保护抗原VP2基因插入火鸡疱疹病毒HVT中获得的载体疫苗,1日龄皮下注射免疫之后．可以同时预防鸡马立克氏病和传染性法氏囊病。本研究探讨了这种新型疫苗对黄羽肉鸡传染性法氏囊病的免疫保护效果,综合实验室免疫试验结果和田间免疫试验结果,威力克免疫对黄羽肉鸡法氏囊发育不会造成损伤;威力克免疫组在21d时IBD抗体水平高于法倍灵免疫组,特别是在21～28d时尤其如此。实验结果表明,威力克免疫能为黄羽肉鸡提供更好的免疫保护,获得更好的经济效益。     

鸡传染性法氏囊病免疫的新突破

鸡传染性法氏囊病(IBD)又称为鸡传染性囊病、甘布罗病,是由传染性法氏囊病毒引起的鸡的一种急性、高度接触性和免疫抑制性的传染病。以突然发病、病程短、发病率高、法氏囊受损和鸡体免疫机能受抑制为特征。1法氏囊疫苗免疫存在的问题成功防控IBD的目的已不再局限于不发生IBD,而是更关注是否对法氏囊的破坏而造成的免疫抑制问题。传统疫苗防控IBD存在几个困惑:母源抗体与免疫时间;母源抗体与疫苗     

利用传染性法氏囊病病毒VP2 ELISA抗体分析孵化场免疫威力克的准确性

威力克(VAXXITEK(R)HVT+IBD)是梅里亚动物保健有限公司于2011年在中国推出的一种新型传染性法氏囊病活载体疫苗,当年即在国内市场销售了近8亿羽份.威力克为载体疫苗,是将传染性法氏囊病(IBD)病毒的VP2基因片段插入火鸡疱疹病毒(HVT)的基因内,重新组成新的疫苗.VP2片段携带宿主保护性抗原决定簇基因,可以诱导免疫系统产生抗IBD的VP2抗体,因此威力克虽然不含有IBD病毒,但免疫后可以激发鸡免疫系统产生抗IBD抗体,从而预防IBD的感染.     

传染性法氏囊病免疫防控技术

传染性法氏囊病(IBD)是由传染性法氏囊病病毒(IBDV)引起的一种急性、高度接触性的家禽传染病,对世界范围内的养鸡业造成了巨大的经济损失。针对IBD的最主要防控技术是疫苗接种,但是随着IBDV变异株及超强毒株的出现,传统疫苗不能对田间复杂的流行情况提供良好的交叉保护,免疫失败情况时有发生,近年来随着基因重组载体活病毒载体等新型疫苗的大量应用,IBD发病率在世界范围内呈下降趋势。本文旨在概述国内外学者对IBDV及其疫苗的研究进展,为IBD免疫防控提供一些思路和参考。     

鸡传染性法氏囊病防治的措施

鸡传染性法氏囊病（IBD）是由传染性法氏囊病毒（IBDV）引起的。致病特性以亚临床型IBD症状为主,最典型的病变是法氏囊迅速萎缩,未见经典毒株所致的高死亡率及典型的腿肌出血等症状。当常规IBD疫苗免疫的鸡群受到变异毒株侵袭时,     

黑龙江省蛋鸡传染性法氏囊病流行病学调查及其免疫防控

鸡传染性法氏囊病(IBD)是一种严重危害鸡的高度接触性传染性免疫抑制性疾病,其病原为传染性法氏囊病病毒.典型症状为颤抖、极度衰弱、腹泻;特征性病变表现为法氏囊出血、水肿,腺胃和肌胃交界处呈条状出血,肾脏肿胀,腿肌和胸肌出血.本病是严重威胁养鸡业的重要传染病之一,常造成巨大经济损失.疫苗免疫是有效防控该病的有效环节之一,但是传统IBD活疫苗的安全性和有效性不能很好兼顾,尤其在母源抗体水平不确定的情况下更为突出.新型传染性法氏囊病活载体疫苗(VAXXITEK)的应用可以解决这一矛盾,具有很好应用前景.     

鸡传染性法氏囊病二价弱毒细胞苗的研制

鸡传染性法氏囊病(IBD)的预防主要靠接种疫苗,我国目前使用的IBD疫苗种类繁多,大多数为IBD血清I型毒株制备的鸡胚组织苗和细胞苗.     

鸡IBD免疫群发生IBD的临床特点和应急处理方法及预防

鸡传染性法氏囊病(IBD)也称传染性囊病或腔上囊炎,是由传染性法氏囊病毒引起的一种幼雏鸡和中雏鸡急性、高度接触性传染病,也是以侵害法氏囊为主的一种急性免疫抑制性传染病。近几年,该病广泛存在于各养殖场区,对幼雏鸡及中雏鸡造成了相当严重的损失。尽管目前已有良好的疫苗免疫,但是一些不科学的免疫程序和操作方法致使免疫鸡群中仍有IBD发生。笔者在兽医临床上遇到许多免疫鸡群发生的IBD病例,现将免疫鸡群发生IBD的临床特点和应急处理方法及预防经验报道如下。1鸡群IBD免疫后发生IBD的类型特点1.1 IBD疫苗反应所致鸡群发生IBD…     

鸡传染性法氏囊病新型疫苗的研制策略

近年来,由于鸡传染性法氏囊病(IBD)超强毒株或变异株的出现,又使本病的发生和流行出现了新的特点,加重了对养鸡业的危害.国内外对IBD的免疫预防进行了大量的研究,对IBD疫苗的研制从未停止过探索,相继研制出可在鸡胚或CEF细胞上培养增殖的弱毒疫苗、灭活苗以及针对病毒主要结构蛋白VP2的基因工程疫苗等,但无论是弱毒疫苗、灭活苗还是基因工程疫苗,都有其各自的局限性,其中最大的问题是疫苗的免疫期短以及在存在母源抗体的情况下,许多疫苗的免疫效果受到干扰.从而在一定程度上影响了推广应用.随着对IBDV分子生物学研究的不断深入,应用生物高新技术研制新型疫苗已成为可能,本文就鸡传染性法氏囊病新型疫苗的研制策略作一探索.     

Molecular characterisation of infectious bursal disease viruses isolated in recent acute outbreaks in Slovenia

In 2004 and then in 2006 several outbreaks of infectious bursal disease (IBD) were reported in broiler and broiler breeder flocks in Slovenia. In this report ten recently emerged IBD viruses (IBDV) were characterised by sequence analysis of the VP2 hypervariable region and compared to previous Slovene IBDV strains from 1995/1996 and to some representative serotype 1 IBDV strains of different pathotypes. On the basis of nucleotide and amino acid identities, phylogenetic analyses and the presence of very virulent IBDV (vvIBDV) conserved amino acid substitutions, all Slovene isolates from recent outbreaks were identified as vvIBDV. Although some unique nucleotide exchanges and amino acid substitutions have been observed, the results of this study indicated that recent vvIBDV isolates are closely related with those from outbreaks in the 1990s. However, acute IBD has not been reported in commercial flocks in Slovenia for some years. This could lead to the conclusion that poor biosecurity and relaxed vaccination could be responsible for the re-emergence of vvIBDV.     

Research on infectious bursal disease--the past, the present and the future

Infectious bursal disease (IBD) virus (IBDV) is the etiological agent of "Gumboro disease". Although first observed about 40 years ago, this disease continues to pose an important threat to the commercial poultry industry. The emergence of antigenic variant as well as very virulent strains in vaccinated flocks considerably stimulated research efforts on both, IBD and IBDV. In this review, some of the recent advances in the understanding of the structure, morphogenesis and molecular biology of the virus as well as in development of new diagnostic approaches and new strategies for vaccination against IBD are briefly summarized.     

传染性法氏囊病病毒广西分离株血清亚型的确定

应用兔制备的抗传染性法氏囊病病毒(IBDV)高免血清,在鸡胚成纤维细胞(CEF)上对从广西发病鸡群分离的4个IBDV代表性流行毒株和2个常用疫苗株进行交叉中和试验。结果表明6个毒株被分为2个血清亚型;根据试验所得的R值,应用聚类分析法分析了各亚型毒株之间的亲缘关系,结果显示目前在广西流行的IBDV野毒株之间以及其与疫苗株间的抗原性存在一定的差异。研究结果对及时掌握广西IBDV流行毒株的抗原变异并为研制更有效的适合本地使用的IBD疫苗提供了科学依据。     

试纸探针条检测鸡传染性法氏囊病疫苗中病毒含量的试验

试纸探针条可识别市售的国产或进口鸡传染性法氏囊病（IBD）代表性疫苗毒株及其鸡胚培养毒或细胞培养或其接种鸡的囊毒，并可检出经甲醛灭活的IBD标准强毒、田野囊毒、鸡胚培养毒或细胞培养毒。活的或灭活待检疫苗水溶液中IBDV的含量越高，试纸探针条上阳性线显现越快、颜色越深且明显；在30分钟的结果观察时间内，该条可检出每0.1mL样品中800ELD50或10^7.0TCID50的病毒含量，该条检测灭活IBDV的效价是AGP测定效价的32倍以上，试纸探针条为估价疫苗中IBDV的含量或疫苗质量提供了一条简便、快速、经济的新途径。     

Virulent vaccine strains of infectious bursal disease virus not distinguishable from wild-type viruses with marker the use of a molecular

Molecular techniques have not only made timely and accurate detection of infectious bursal disease viruses (IBDVs) possible but also have allowed the identification of viral strains. Previously, we identified a genetic marker that distinguished wild-type IBDV strains from vaccine strains of the virus. The marker was an NgoM IV restriction enzyme site in the VP2 gene that was present in 10 wild-type viruses but not 16 vaccine strains of IBDV. On the basis of that study, we concluded that the NgoM IV marker could be useful in the identification of wild-type potentially pathogenic strains of this virus. Because virulent (hot) vaccine strains of IBDV are used to vaccinate commercial poultry, it was important to determine if the NgoM IV marker was present in these virulent vaccines. The infectious bursal disease Blen and Bursa Vac virulent vaccines were examined and determined to contain the marker. We concluded that the presence of this marker was not unique to wild-type strains of the virus. The absence of the NgoM IV marker, however, was consistent with some level of attenuation, and its presence appears to be consistent with virulent IBDV strains.     

Heteroduplex mobility assay for genotyping infectious bursal disease virus

A heteroduplex mobility assay (HMA) was developed to genotype infectious bursal disease virus (IBDV). This method analyzed 390-base pair (bp) polymerase chain reaction (PCR) products, encompassing the hypervariable region of the VP2 gene. IBDV strains from the United States and other countries were analyzed. The HMA was able to differentiate standard, antigenic variants and very virulent strains of IBDV. Minor differences between different strains from the same subtype were also detected. Close relationships between field IBDV with vaccines prepared with Delaware E strain were determined by HMA. The results obtained by HMA were confirmed by restriction fragment length polymorphism (RFLP) and phylogenetic analysis of nucleotide sequences. The HMA proved to be a useful technique to rapidly genotype different field strains of IBDV and should prove to be a useful tool in epidemiologic studies.     

Infectious bursal disease virus variant from commercial Leghorn pullets

An infectious bursal disease virus (IBDV) was isolated from 39-to-43-day-old commercial leghorn pullets suspected of having infectious bursal disease (IBD). These chickens had been vaccinated with a commercial live IBDV vaccine at 28 and 35 days of age. An isolate designated IN was recovered using specific-pathogen-free (SPF) chickens and the BGM-70 established cell line. Experimental studies using SPF chickens vaccinated with either inactivated vaccines made from the vaccine strain used in the problem flock or a standard-type vaccine indicated no protection against the IN isolate. However, two variants and another standard-type vaccine induced protection against the IN isolate. Cross-neutralization tests indicated that the IN isolate differed antigenically from commercial vaccine strains and was related to the variant IBDV strains recently isolated from broilers. To our knowledge, this is the first report of a variant IBDV recovered from commercial layer chickens in the United States.