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101.
“禽疫苗免疫增强剂”与鸡新城疫IV系活疫苗同时免疫雏鸡后 ,其血液中的HI抗体效价和ANAE T淋巴细胞百分比持续性高于单独使用IV系活疫苗免疫雏鸡 ,且在大部分时间内差异显著 (P <0 0 5 )。在攻毒试验中 ,加免疫增效剂组保护率为 93 3% ,单独免疫组保护率为 80 %。  相似文献   
102.
哺乳动物中除豚鼠外GnRH-Ⅰ的主要序列和结构都是完全一致的,所以GnRH-Ⅰ疫苗的应用范围广。在动物去势及避孕和人类免疫治疗研究中显示了其无可比拟的优越性。本文综述了GnRH-Ⅰ疫苗的免疫机理、免疫效果的影响因素及其商业化的困境。  相似文献   
103.
Little is known about the safety and efficacy of extra-label use of the modified live porcine reproductive-and-respiratory syndrome (PRRS) virus vaccine in gestating sows. Our purpose was to determine the impact of vaccination on reproductive performance in 54 herds in Ontario, Manitoba (Canada) and the mid-western United States that were PRRS-positive, PRRS-negative, or concurrently affected by an outbreak of PRRS when initially vaccinated. Majority-vaccinated herds vaccinated ≥50% but <100% of sows at one time, and limit-vaccinated herds vaccinated <50% of sows at one time. Most majority-vaccinated herds did not vaccinate sows in late gestation, and none vaccinated during the initial PRRS outbreak. Numbers of pigs born alive and weaned decreased when pregnant sows were vaccinated. The effect of vaccination on productivity in the gestation following vaccination depended on the vaccination protocol.  相似文献   
104.
强效艾美耳牌鸡球虫苗的免疫效果   总被引:23,自引:5,他引:18  
在实验条件下,研究了强效艾美耳牌鸡球虫苗对平养鸡群的免疫效果。实验1比较了免疫鸡群和对照鸡群在接种后1、2、3、4、5、6周的肠道病变分,结果表明免疫鸡群较自然感染建立免疫的对照鸡群的免疫整齐度高,判断依据是免疫后2周盲肠细小、内容物亦少的眼观指标。实验2比较了免疫鸡群、不免疫不用药鸡群、不免疫用药鸡群在攻虫后的三处肠道病变,结果表明免疫鸡群对大剂量卵囊攻击有很强的抵抗力。实验3比较了免疫鸡群、不  相似文献   
105.
Caprine coccidiosis, affecting mainly young goat kids around the weaning period, is worldwide the most important disease in the goat industry. Control of caprine coccidiosis is increasingly hampered by resistances developed against coccidiostatic drugs leading to an enhanced need for anticoccidial vaccines. In the current study we conducted an oral immunization trial with live attenuated sporulated Eimeria ninakohlyakimovae oocysts. Sporulated E. ninakohlyakimovae oocysts were attenuated by X-irradiation technique. The experimental design included a total of 18 goat kids divided into the following groups: (i) animals immunized with attenuated E. ninakohlyakimovae oocysts at 5 weeks of age and challenged 3 weeks later with non-irradiated homologous oocysts (group 1); (ii) animals infected with non-attenuated E. ninakohlyakimovae oocysts at 5 weeks of age and challenged 3 weeks later with non-attenuated homologous oocysts (group 2); (iii) animals primary-infected with untreated E. ninakohlyakimovae oocysts at 8 weeks of age (control of the challenge infection, group 3); (iv) non-infected control animals (group 4). Goat kids immunized with live attenuated E. ninakohlyakimovae oocysts (group 1) excreted significantly less oocysts in the faeces (95.3% reduction) than kids infected with non-attenuated ones (group 2). Furthermore, immunization with live but attenuated oocysts resulted in ameliorated clinical coccidiosis compared to goat kids infected with untreated oocysts (group 2) and resulted in equally reduced signs of coccidiosis after challenge infection compared to acquired immunity driven by non-attenuated oocysts. Overall, the present study demonstrates for the first time that live attenuated E. ninakohlyakimovae oocysts orally administered showed almost no pathogenicity but enough immunogenicity in terms of immunoprotection. Importantly, vaccinated animals still shed low amounts of oocysts, guaranteeing environmental contamination and consecutive booster infections to sustain ongoing immunity.  相似文献   
106.
Two field studies were conducted to investigate the influence of age on the efficacy of vaccination against Porcine Circovirus Diseases (PCVD) in animals with high levels of maternally derived antibodies (MDA). A total of 416 piglets (Study 1) and 600 piglets (Study 2) were randomly allocated to one of three groups. Two groups in each study received a single dose of a PCV2 subunit vaccine, one group at 1 week old and the other at 3 weeks of age. The third group was left untreated. Animals vaccinated at 3 weeks of age showed a significantly higher average daily weight gain and significantly reduced viraemia following PCV2 infection than the respective control groups. This difference was not observed in pigs vaccinated at 1 week of age. Furthermore, only animals vaccinated at 3 weeks of age showed an increased serological response and a higher frequency of IgM-positive animals compared with controls. The data indicated that PCV2 vaccination in the presence of high MDA levels is efficacious when used in 3-week old but not in 1-week old pigs. As the range of MDA titres of pigs vaccinated at both 1 and 3 weeks of age were comparable, the data suggest that PCV2 vaccine efficacy was independent of the level of MDA. It appears that other age-related factors affecting the active and passive transfer of immunity may perhaps have interfered with the efficacy of the vaccine in 1-week old piglets. These findings have implications for future PCV2 vaccine testing and administration strategies.  相似文献   
107.
选择14日龄雏鸡110只,随机均分为11组,Ⅰ组为对照组,Ⅱ~Ⅺ为试验组,各组雏鸡在14日龄时均颈部皮下注射鸡ND—La Sota疫苗0.2ml/只.试验组雏鸡同时经口投服由不同配方和比例黄芪多糖、淫羊藿多糖、左旋咪唑、维生素E和亚硒酸钠制备的10种缓释复方免疫增强剂1粒,对照组雏鸡不投服。在免疫前后不同时间采血测定各组雏鸡ND—HI抗体效价和T淋巴细胞ANAE阳性率.结果表明制备的10种缓释复方免疫增强剂均不同程度地提高了雏鸡ND—HI抗体效价和T淋巴细胞ANAE阳性率.其中以X组和Ⅺ组配方效果最好,为今后研制缓释复方免疫增强剂奠定了基础。  相似文献   
108.
鸭肝炎病毒A_(66)弱毒株的研究   总被引:1,自引:0,他引:1  
鸭肝炎病毒I型A_(66)鸡胚化弱毒株,对雏鸭安全、稳定.鸡胚混合毒滴度为10~(7.36-8.09)CELD50/0.1毫升.以1.8万DLD50/0.1毫升的强毒攻击,其半数免疫量为10~(6.16)MID50/0.1毫升;皮下注射的免疫产生期为接种后48小时.免疫持续期测至45天,全部保护.用本弱毒苗免疫雏鸭,可预防I型鸭病毒性肝炎的发生.以该弱毒苗高度免疫成年鸭或猪血制备的抗血清,对雏鸭能产生坚强的被动免疫力.  相似文献   
109.
免疫佐剂研究进展   总被引:1,自引:0,他引:1  
佐剂是能够增强免疫应答或改变免疫应答类型的物质,本身可以具有免疫原性,也可以没有免疫原性.佐剂种类很多,如氢氧化铝佐剂、细菌佐剂、脂多糖、细胞因子等.综述了氢氧化铝佐剂、多糖佐剂、细胞因子佐剂以及一些新型佐剂的研究进展,旨在为今后开展疫苗和佐剂的相关研究提供参考.  相似文献   
110.
The recombinant β-tubulin of Pseudocohnilembus persalinus was investigated to test whether tubulin could be a suitable antigenic target against scuticociliatosis. The cDNA of P. persalinus β-tubulin has an open reading frame of 1332 bp and had 15 TAA triplets code for glutamine (Q). All 15 TAA/Q triplets of the β-tubulin cDNA were mutated to universal CAA/Q triplets by site-directed mutagenesis and the mutated β-tubulin was expressed in Escherichia coli as a fusion with glutathione S-transferase (GST-BTU). In Western blot analysis, rat sera immunized with recombinant GST-BTU reacted with reduced β-tubulin of P. persalinus. The immunized rat sera showed higher parasiticidal activity than those of control. Ciliates preincubated with heat-inactivated immune sera showed significantly lower proliferation than ciliates preincubated with control sera when exposed to naïve rat sera as a complement source. The present results suggest that the recombinant β-tubulin of scuticociliates may be used as a target antigen for development of vaccine against scuticociliatosis.  相似文献   
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