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1.
鸡马立克氏病活疫苗免疫效力比较试验   总被引:1,自引:0,他引:1  
用HVT冻干苗、HVT细胞结合苗、CVI988细胞结合苗、SB1+FC126双价活疫苗、301B/1+FC126双价活疫苗和Z4+FC126双价活疫苗等6种鸡马立克氏病(MD)疫苗免疫SPF白来航鸡或普通伊莎鸡,用鸡马立克氏病病毒(MDV)强毒GA株、京-1血毒以及鸡马立克氏病超强毒vvMDV-Md5毒株分别攻击进行免疫效力比较试验。试验表明,MD单价苗的免疫效力强弱顺序依次是CVI988、HVT细胞结合苗和HVT冻干苗,这3种MD单价苗均能给免疫鸡群提供有效的免疫保护力。SB1+FC126、Z4+FC126和301B/1+FC126等3种MD双价苗免疫效力显著高于MD单价苗,均能给免疫鸡群提供较强的免疫保护力,并能有效地抵抗vvMDV-Md5毒株的致瘤作用。Z4+FC126和301B/1+FC126MD双价苗免疫效力无显著差异  相似文献   

2.
鸡马立克氏病单价活疫苗免疫效力比较试验   总被引:1,自引:0,他引:1  
用农业部南京药械厂和三家外国动物保健品公司生产的4种火鸡疱疹病毒(HVT)冻干苗、实验室制备的CVI988细胞结合苗和HVT细胞结合苗等6种鸡马立克氏病(MD)单价活疫苗免疫1日龄SPF白来航鸡,8日龄时用鸡马立克氏病强毒(vMDV)GA株攻击,同时以Z4+FC126双价活疫苗作对照,进行免疫效力比较试验。结果表明,6种MD单价活疫苗均能使免疫鸡群获得对vMDV攻击的免疫保护力,免疫效力强弱顺序依  相似文献   

3.
分别以血清型Ⅱ型马立克氏病病毒(MDV)疫苗株(Z4、SB1)、血清Ⅲ型火鸡疱疹病毒(HVT)疫苗株(FC126)及二价疫苗(Z4+FC126、SB1+FC126)免疫鸡群,用琼脂扩散试验(AGPT)检查各鸡群MDV强毒攻击后不同时期的羽囊抗原。结果,二价苗能使试验鸡羽毛囊强毒排出高峰推迟,排毒率显著下降。  相似文献   

4.
用马立克氏病病毒BJMDV-1株分别攻击由CVI988/B5、HCV2/B5和FC126/B5毒株组成的,剂量配比不相同的马立克氏病(MD)三价活疫苗免疫的鸡群,结果表明MD三价活疫苗中CVI988/B5、HCV2/B5及FC126/B5毒株的合适配比为2:1:2。按照此剂量配比制备的MD三价活疫苗,用RB1B超强毒株进行攻毒,当RB1B攻毒对照组MD阳性率为85.71%时,MD三价活疫苗的半数保护剂量(PD50)均数为111PFU/只,95%置信区间为585~53PFU/只的范围内,并确定MD三价活疫苗的免疫剂量为2500PFU/只。用该剂量对鸡进行MD三价活疫苗免疫,可使鸡体产生抗RB1B超强毒株攻击的坚强免疫力。  相似文献   

5.
HVT Fc-126株及其克隆株免疫一日龄有母源抗体的雏鸡后,结果三个大斑克隆株产生的毒血症水平高于HVTFc-126株和小斑克隆株。所有同群未免疫对照鸡均无毒血症产生。母源抗体在21天时仍可测到,且明显影响毒血症的产生,并使毒血症的高峰期推迟。各克隆株接种后具有中和母源抗体的能力。用MD京-1株强毒攻击结果表明:抗攻毒保护力与鸡体内毒血症水平呈正相关,而与中和抗体水平似乎无关,母源抗体不能保护雏  相似文献   

6.
法氏囊提取物增强IBD活疫苗免疫效果观察   总被引:4,自引:1,他引:3  
用鸡法氏囊活疫苗滴鼻点眼免疫35日龄SPF鸡,同时以不同方式接种囊提取物,试验结果表明,法氏囊提取物能明显增强鸡法氏囊活疫苗的免疫效果;经滴鼻点眼途径给予法氏囊提取物能够显著提高IBD免疫鸡的特异保护力。  相似文献   

7.
采用弱毒活疫苗加强免疫,通常是根在产蛋期间采用新城疫(ND)或传染性支气管炎(IB)弱毒活疫苗加强免疫接种,以提高免疫保护力。对免疫学机理的研究清楚地表明:活疫苗加强免疫接种能够刺激机体的细胞免疫与体液免疫,包括增强局部免疫反应(眼、气管)与循环(血液)抗体的保护水平。在鸡群生长期继适当的弱毒活疫苗营免后,采用灭活疫苗加强免疫仅能够刺激机体产生一致的高水平的循环抗体,这些高效价的抗体随着时间的推移而逐渐消失,从而对老龄鸡群相对缺乏保护力。为什么局部免疫保护如此重要?因为试验结果证实:即使在测不出循…  相似文献   

8.
HVTFc-126株及其克隆株免疫一日龄有母源抗体的雏鸡后,结果三个大斑克隆株产生的毒血症水平高于HVTFc-126株和小斑克隆株。所有同群未免疫对照鸡均无毒血症产生。母源抗体在21天时仍可测到,且明显影响毒血症的产生,并使毒血症的高峰期推迟。各克隆株接种后具有中和母源抗体的能力。用MD京-1株强毒攻击结果表明:抗攻毒保护力与鸡体内毒血症水平呈正相关,而与中和抗体水平似乎无关,母源抗体不能保护雏鸡抵抗强毒的攻击。  相似文献   

9.
本研究以新城疫病毒 F 基因的c D N A 与真核表达载体pc D N A3 重组,构建了新城疫病毒 F基因疫苗。采用不同剂量接种 S P F鸡后,通过抗体监测和强毒攻击试验,分析了其诱导的体液免疫应答及免疫保护作用。结果表明,接种剂量为100μg、200 μg 时,试验鸡在免疫后第 2 周出现较明显的抗体反应,接种剂量为 10 μg 时抗体变化不明显。以标准强毒 F48 E9 攻击后,空白对照组及接种剂量为10 μg 和100 μg 组的鸡只全部发病死亡,未获得免疫保护;而200 μg 组鸡只全部存活,获得完全免疫保护。表明基因免疫效果与接种的剂量有密切的关系。  相似文献   

10.
成疫病毒F基因疫苗接种剂量的研究   总被引:1,自引:0,他引:1  
以新城疫病毒F基因的cDNA与真核表达载体pcDNA3重组,构建了新城疫病毒F基因疫茵。采用不同剂量接种SPF鸡后,通过抗体监测和强毒攻击试验,分析了其诱导的体液免疫应答及免疫保护作用。结果表明,接种剂量为100,200ug时,试验鸡在免疫后第2周出现较明显的抗体反应,接种剂量为10ug时抗体变经不明显。以标准强毒F48E9攻击后,空白对照组及接种剂量为10,100ug组的鸡只全部发病死亡,未获得  相似文献   

11.
Comparative 50% protective dose (PD50) assays were performed using a plaque-purified preparation of Marek's disease virus (MDV) strain CVI-988 at the 65th chicken embryo fibroblast (CEF) passage level (MDV CVI-988 CEF65 clone C) and three commercial MD vaccines: herpesvirus of turkeys (HVT) FC126, MDV CVI-988 CEF35, and a bivalent vaccine composed of HVT FC126 and MDV SB-1. In addition, comparative PD50 assays were performed in groups of chickens with maternal antibody to each of the three vaccines. Three representatives of the newly emerged biovariant very virulent (vv) MDV strains-RB/1B, Tun, and Md5-were employed as challenge virus. The experiments made feasible the differentiation between virulent MDV and vvMDV strains, within serotype 1. Vaccination with CVI-988 clone C vaccine resulted in PD50 estimates of about 5 plaque-forming units (PFUs) against challenge infection with each of the three vvMDV strains. The PD50 estimate of CVI-988 clone C vaccine was 12-fold below the PD50 of HVT FC126. The protective synergism of bivalent vaccine, composed of HVT and SB-1, was confirmed by groups given the lowest vaccine doses. The bivalent vaccine, however, resulted in incomplete protection in groups given the highest vaccine doses. Homologous maternal antibodies to serotype 1 caused a fivefold increase in the PD50 estimate of CVI-988 clone C. Heterologous maternal antibodies against HVT did not interfere with efficacy of CVI-988 clone C vaccination. However, the combination of maternal antibodies against both HVT and SB-1 (serotypes 2 and 3) showed a strong adverse effect on CVI-988 clone C vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

12.
R L Witter 《Avian diseases》1987,31(4):752-765
Attempts were made, through selection of optimum viral strains, to develop improved vaccines against Marek's disease (MD). Seven attenuated serotype 1 strains and 22 avirulent serotype 2 strains, both alone and in combination with the FC126 strain of serotype 3, were screened for protective efficacy against challenge with virulent and very virulent MD viral strains. The three viruses selected as most promising were evaluated alone and in various combinations and compared with commercially available vaccines, including FC126, bivalent (FC126 + SB-1), and CV1988/C, in 12 separate assays. Two of these new viruses--301B/1 (serotype 2) and Md11/75C/R2 (serotype 1)--were exceptionally protective compared with prototype vaccine strains. Four new monovalent and polyvalent vaccines based on these two isolates protected chickens better than FC126 alone or CV1988/C alone. Three of these new vaccines provided better protection than the bivalent (FC126 + SB-1) vaccine. Protective synergism was noted commonly between viruses of serotypes 2 and 3 but only sporadically between serotypes 1 and 2 or between serotypes 1 and 3. Strain CVI988/C was protective but was no better than FC126 alone, and it was less effective than bivalent (FC126 + SB-1) vaccine, even when used as a bivalent vaccine with FC126 or SB-1.  相似文献   

13.
The efficacies of trivalent (Md11/75C + SB-1 + HVT), bivalent (SB-1 + HVT), and turkey herpesvirus (HVT) vaccines against Marek's disease (MD) were compared in commercial broiler flocks in four trials involving 11 farm locations and 486,300 chickens. In all four trials, chickens receiving polyvalent vaccines had lower leukosis (MD) condemnation rates than chickens vaccinated with HVT alone; when data were summarized for each vaccine type in each trial, condemnation rates for the bivalent- or trivalent-vaccinated groups were 56-96% (mean 78%) lower than those for HVT-vaccinated chickens. Polyvalent vaccination was clearly mor efficacious than HVT in 8 of 11 individual farms, although it did not always reduce leukosis condemnations to acceptable levels. Body weights of chickens vaccinated with polyvalent vaccines did not differ consistently from those vaccinated with HVT. Chickens inoculated with the trivalent vaccine had slightly lower overall leukosis condemnation rates (0.24%) than those inoculated with the bivalent vaccine (0.45%) in trials 1-3, where direct comparisons were made. Bivalent vaccines containing either 1,500 or 200 plaque-forming units of SB-1 virus were equally effective; thus, HVT may need to be supplemented with only small amounts of SB-1 to obtain the benefits of protective synergism. SB-1 virus did not appear to carry over from polyvalent-vaccinated flocks to subsequent HVT-vaccinated flocks in the same houses, even when old litter was used.  相似文献   

14.
Sung HW 《Avian diseases》2002,46(3):517-524
The incidence of Marek's disease (MD), an important neoplastic disease of chickens, suddenly increased in 1997 in Korea. Most MD cases of this country were detected in chickens over 20 wk of age. Five MD viruses were isolated from field flocks in which severe MD losses had occurred, and one of the viruses was studied to compare its pathotype with the prototype JM strain. The isolate KOMD-IC induced severe depression not only in body weight but also in relative bursal weight, and the depression by KOMD-IC was more severe than that induced by JM strain. In addition, the incidence of MD tumor caused by KOMD-IC was higher than that caused by the JM strain. The protective capacity of several MD vaccines was studied against challenge with KOMD-IC. The protective levels of several MD vaccines such as herpesvirus of turkeys (HVT), HVT plus SB1, and Rispens were usually lower against challenge with KOMD-IC than those challenged with JM strain, even if the chickens vaccinated with serotype 1 were not completely protected against challenge with KOMD-IC. The above results indicate that the virulence of KOMD-IC isolated recently was increased, and the increase of MD outbreak in Korea may be related to the virulence increase of the virus. Various MD vaccine programs were applied to reduce MD loss to a broiler breeder farm where severe MD loss had occurred. Serotype 1 vaccine could dramatically decrease the mortality due to MD, and the best results were obtained from the flocks vaccinated with bivalent vaccine of Rispens and HVT.  相似文献   

15.
分别以7种鸡MD疫苗免疫SPF鸡和狼山鸡,用琼脂扩散试验(AGP)检查鸡群MDV强毒攻击后不同时期的羽囊抗原,结果表明,免疫组鸡羽囊排毒高峰推迟,排毒率下降,排毒高峰维持时间短,不同疫苗免疫不同品种鸡后排毒情况有差异,CVI988和两种二价苗效果优于HVT苗。  相似文献   

16.
Dilution of Marek's disease (MD) vaccines is a common practice in the field to reduce the cost associated with vaccination. In this study we have evaluated the effect of diluting MD vaccines on the protection against MD, vaccine and challenge MD virus (MDV) kinetics, and body weight when challenged with strains Md5 (very virulent MDV) and 648A (very virulent plus MDV) by contact at day of age. The following four vaccination protocols were evaluated in meat-type chickens: turkey herpesvirus (HVT) at manufacturer-recommended full dose; HVT diluted 1:10; HVT + SB-1 at the manufacturer-recommended full dose; and HVT + SB-1 diluted 1:10 for HVT and 1:5 for SB-1. Vaccine was administered at hatch subcutaneously. One-day-old chickens were placed in floor pens and housed together with ten 15-day-old chickens that had been previously inoculated with 500 PFU of either Md5 or 648A MDV strains. Chickens were individually identified with wing bands, and for each chicken samples of feather pulp and blood were collected at 1, 3, and 8 wk posthatch. Body weights were recorded at 8 wk for every chicken. Viral DNA load of wild-type MDV, SB-1, and HVT were evaluated by real time-PCR. Our results showed that dilution of MD vaccines can lead to reduced MD protection, reduced relative body weights, reduced vaccine DNA during the first 3 wk, and increased MDV DNA load. The detrimental effect of vaccine dilution was more evident in females than in males and was more evident when the challenge virus was 648A. However, lower relative body weights and higher MDV DNA load could be detected in chickens challenged with strain Md5, even in the absence of obvious differences in protection.  相似文献   

17.
Marek's disease (MD) vaccines representing serotypes 2 (SB-1 strain of MD virus) and 3 (FC-126 strain of turkey herpesvirus) were administered to 1-day-old MD-susceptible chicks that either were free of antibodies or carried maternally derived antibodies against SB-1, FC-126, or a serotype-1 MD virus, CU-2 strain. Homologous antibodies delayed the development of vaccine virus viremias and inhibited vaccinal immunity, as judged by protection against challenge with the virulent JM-10 strain of MD virus 7 days postvaccination. Heterologous antibodies had little effect on vaccine responses. Antibodies were shown to interfere with both cell-associated and cell-free vaccine virus.  相似文献   

18.
Field trials with a bivalent vaccine (HVT and SB-1) against Marek's disease   总被引:3,自引:0,他引:3  
White leghorn chickens on five farms were given a bivalent Marek's disease (MD) vaccine consisting of turkey herpesvirus (HVT) and SB-1 (a nononcogenic MD virus); other chickens received only HVT. The farms had histories of "vaccination failures," presumably owing to an exceptionally virulent challenge MD virus. The bivalent vaccine uniformly protected chickens better than HVT alone between 12 and 16-20 weeks of age, when serious MD losses occurred. During that period, total mortality in groups given both viruses ranged from 0.39 to 1.26% (mean 0.86%), whereas that in HVT-vaccinated groups not exposed to SB-1 varied from 1.92 to 7.44% (mean 3.43%). Chickens in pens or rows with close contact to those given bivalent vaccine also had low MD mortality rates (0.46-1.06%, mean 0.77%), probably from the spread of SB-1.  相似文献   

19.
Marek's disease (MD) is a lymphoproliferative disease of domestic chickens caused by a highly infectious, oncogenic alpha-herpesvirus known as Marek's disease virus (MDV). MD is presently controlled by vaccination. Current MD vaccines include attenuated serotype 1 strains (e.g., CVI988/Rispens), avirulent serotype 2 (SB-1), and serotype 3 (HVT) MDV strains. In addition, recombinant MDV strains have been developed as potential new and more efficient vaccines to sustain the success of MD control in poultry. One of the candidate recombinant MDV strains, named rMd5deltaMeq, was derived from Md5, a very virulent strain of MDV lacking the MDV oncogene Meq. Our earlier reports suggest that rMd5deltaMeq provided protection equally well or better than commonly used MD vaccines in experimental and commercial lines of chickens challenged with very virulent plus (vv+) strains of MDV. In this study, maternal antibody-positive (trial 1) and negative (trial 2) chickens from a series of relatively MD resistant lines were either vaccinated with the rMd5deltaMeq or CVI988/Rispens followed by infection of a vv+ strain of MDV, 648A, passage 10. This report presents experimental evidence that the rMd5deltaMeq protected significantly better than the CVI988/Rispens (P < 0.01) in the relatively resistant experimental lines of chickens challenged with the vv+ strain of MDV. Together with early reports, the rMd5deltaMeq appeared to provide better protection, comparing with the most efficacious commercially available vaccine, CVI988/Rispens, for control of MD in lines of chickens regardless of their genetic background.  相似文献   

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