不同禽流感病毒含量的新-流二联灭活疫苗免疫SPF鸡后抗体水平的监测

将未浓缩的新城疫抗原分别与未浓缩的、浓缩3倍、浓缩6倍的禽流感抗原混合,并制备成三组鸡新城疫、禽流感（H9N2 HP株）二联灭活疫苗（简称新-流二联灭活疫苗）,分别免疫21日龄SPF鸡,每羽0.3 mL,同时设置未免疫的空白对照组,免疫组与对照组均在免疫前及免疫后7、14、21、28、35 d进行采血,检测新城疫和禽流感抗体。结果发现,各免疫组在免后不同日龄的新城疫抗体基本一致,禽流感病毒抗原浓缩倍数越高（即禽流感病毒含量越高）的新-流二联灭活疫苗,免后14、21 d的抗体也越高;从免后21 d开始,各免疫组的禽流感抗体水平差异逐渐减小,免疫后禽流感抗体水平的高低可以反映该疫苗的免疫效果。试验结果表明,该疫苗可以通过浓缩提高抗原病毒含量的方法来提高免后早期抗体水平,取得良好的早期免疫效果。     

鸡新城疫和禽流感(H9亚型)二联灭活疫苗不同佐剂的免疫效果试验

为评价鸡新城疫和禽流感(H9亚型)二联灭活疫苗不同佐剂的免疫效果,选用Marcol 52、T1和SNB白油及S71油佐剂与鸡新城疫病毒和禽流感病毒混合制成灭活疫苗,免疫适龄SPF鸡,比较不同佐剂对鸡的安全性及新城疫和禽流感的血凝抑制(HI)抗体水平。结果表明,4种佐剂疫苗的安全性、稳定性良好;应用T1白油佐剂的灭活疫苗,免疫SPF鸡产生的新城疫和禽流感HI抗体水平优于其他佐剂,免疫后2周检测新城疫和禽流感的抗体水平均合格,确定为最佳白油佐剂。     

肉鸡专用新流二联灭活疫苗的实验研究及临床使用效果研究

利用新型101佐剂制备肉鸡专用新流二联灭活疫苗,与进口白油佐剂新流二联灭活疫苗进行SPF鸡、AA肉鸡免疫比较,结果表明:试验一,SPF鸡10日龄免疫,免疫后7d,肉鸡专用新流组H9、ND抗体水平明显优于对照组;试验二,AA肉鸡7日龄免疫,肉鸡专用新流组禽流感H9抗体水平明显优于对照组,新城疫抗体对比不明显;试验三,AA肉鸡不同公司不同免疫日龄(1日龄、7日龄免疫)对比试验,23、30、37日龄检测新城疫、禽流感H9抗体,齐鲁肉鸡专用新流禽组流感H9抗体产生速度比同类产品及空白对照差异显著,1日龄免疫效果对比更明显;新城疫抗体对比差异不显著;试验四,田间7日龄免疫对比试验,26日龄抽检各舍抗体,齐鲁肉鸡专用新流H9抗体明显优于该公司新流,新城疫对比不明显。结果表明,齐鲁肉鸡专用新流二联灭活疫苗更适合于商品肉鸡免疫,1日龄免疫对比更明显。     

新-流二联灭活疫苗不同方法免疫后抗体水平检测

为探讨鸡新城疫-禽流感(H9N2 HP株)二联灭活疫苗与禽流感抗体不同组合方法免疫商品蛋鸡和商品肉鸡后抗体水平变化规律,试验分别采用A、B、C三种方法免疫商品蛋鸡与商品肉鸡各40羽,A免疫方法为只接种新-流二联灭活苗,B免疫方法为接种新-流二联灭活苗的同时注射禽流感抗体,C免疫方法为接种新-流二联灭活苗7 d后注射禽流感抗体,D组为空白对照组,各组均于免前及免后2d、6d、10d、14d、21d、28d、35d采血检测新城疫与禽流感抗体水平.结果发现,商品蛋鸡与商品肉鸡各免疫组,免后新城疫抗体均先开始下降,免后第10 d抗体开始上升,第14 d开始快速上升,第35 d达到最高,蛋鸡组最高达8log2,而肉鸡组最高达7log2.商品蛋鸡组中配合注射禽流感抗体免疫组,禽流感抗体先上升,然后下降,再继续上升,禽流感抗体保持较高的水平,不低于3log2.而未注射抗体组,禽流感抗体先下降,至第10 d下降至2log2以下,然后开始快速上升.而商品肉鸡各组禽流感抗体免后均开始下降,未注射抗体组,下降至第10 d后开始上升,注射抗体组免后第10 d时下降的幅度比未注射抗体组小,且下降至第15 d后才开始上升.说明商品蛋鸡免疫新-流二联灭活疫苗时配合注射禽流感抗体,短期内对机体禽流感抗体水平提升明显,而在商品肉鸡上配合注射流感抗体对机体禽流感抗体水平提升不明显.     

不同油佐剂ND-AI二联苗及ND-IB-EDS三联苗比较试验

对用两种不同油佐剂(10号白油佐剂及NL白油佐剂)制备出的鸡新城疫(ND)-H9亚型禽流感(AI(H9))型二联灭活疫苗及鸡新城疫(ND)-传染性支气管炎(IB)-减蛋综合征(EDS)三联灭活疫苗进行了物理性状、安全性及效力比较试验。结果显示,这两种不同油佐剂制备出的二联苗及三联苗均为乳白色,剂型为油包水型,性状稳定,NL油佐剂疫苗的黏度低于10号白油佐剂疫苗;用两种油佐剂疫苗接种SPF鸡后,均未出现任何局部及全身不良反应;NL白油佐剂疫苗诱导产生的ND、IB、AI(H9)及EDS HI抗体滴度均高于10号白油佐剂疫苗,提高幅度为0.2 log2～2.2 log2;NDV及AIV(H9)强毒攻击后,两种不同油佐剂疫苗免疫组鸡均10/10保护,NDV攻毒对照组全部死亡,AIV(H9)攻毒对照组鸡分毒全部呈病毒阳性。     

一种免疫增强剂对新-流二联灭活苗抗体消长规律的影响

免疫增强剂是一种能增加疫苗免疫效果的生物活性物质。试验A组为添加了免疫增强剂的新城疫、禽流感(H9亚型)二联灭活疫苗(La Sota株+HP株),试验B组为未添加免疫增强剂的新城疫、禽流感(H9亚型)二联灭活疫苗(La Sota株+HP株),分别比较A组与B组的抗体水平。试验结果表明:7日龄SPF鸡A组抗体与B组抗体无差异;在28日龄SPF鸡上:免后10、15、21、28、35 d,ND部分A组抗体比B组分别高0.2log2、0.6log2、1.5log2、0.9log2、0.5log2,AI部分抗体高出0.1log2、0.3log2、1.2log2、1.0log2、0.6log2;在7日龄商品蛋鸡上A组抗体比B组抗体在免后15、21、28、35 d,ND部分抗体高出1.6log2、2.0log2、1.9log2、3.7log2,AI部分分别高1.3log2、2.7log2、1.8log2、2.0log2。     

不同剂型禽流感疫苗对蛋鸡免疫效果的分析与讨论

使用重组禽流感病毒灭活疫苗和禽流感-新城疫重组二联活疫苗对鸡禽流感进行免疫攻毒试验,通过血凝和血凝抑制(HI)试验技术检测机体内两种不同剂型疫苗的禽流感抗体水平,从中选出最佳免疫效果的疫苗。结果显示,禽流感病毒灭活疫苗优于禽流感-新城疫重组二联活疫苗,建议在防控禽流感时使用前者。     

乳酸杆菌肽聚糖对鸡新城疫油苗和禽流感油苗的免疫增强作用的研究

该试验提取2株乳酸杆菌L．casei zhang和MC2-1的肽聚糖作为佐剂,按不同剂量添加到新城疫油乳剂灭活疫苗及禽流感（H5）亚型油乳剂灭活疫苗中。用此2种加佐剂的油乳剂灭活疫苗对鸡进行免疫,每组20只,分别于15日龄和28日龄进行新城疫组和禽流感组首免,再分别于首免后2周加强免疫,在二免后的第7天与第14天检测血清抗体HI水平。结果表明,与对照组相比试验各组抗体水平均达到显著或极显著水平,可提高抗体水平2^0.33-2^2.50。随着细菌肽聚糖量的增加,各试验组在提高抗体水平上也增加。2株乳酸杆菌肽聚糖对鸡接种新城疫油乳剂灭活疫苗和禽流感（H5）亚型油乳剂灭活疫苗具有免疫增强作用。     

新流二联灭活疫苗与禽流感抗体不同组合免疫产蛋鸡、肉鸡后的抗体水平监测

为探讨鸡新城疫、禽流感(H9N2 HP株)二联灭活疫苗与禽流感抗体不同组合免疫商品蛋鸡与商品肉鸡后的抗体消长规律,试验选用商品蛋鸡与商品肉鸡各40只,商品蛋鸡随机分为A、B、C、D组,商品肉鸡随机分为E、F、G、H组,每组10只,A、E组鸡于7日龄颈部皮下注射新流二联灭活疫苗0.25 m L/只;B、F组鸡于7日龄颈部皮下注射新流二联灭活疫苗0.25 m L/只,同时肌肉注射0.5 m L/只的禽流感抗体;C、G组鸡于7日龄颈部皮下注射新流二联灭活疫苗0.25 m L/只,于免疫后第7天肌肉注射0.5 m L/只的禽流感抗体;D、H组鸡不免疫,作为阴性对照组。各组鸡均于免疫前及免疫后的第2,6,10,14,21,28,35天采血检测新城疫与禽流感抗体水平。结果表明:商品蛋鸡B、C组在免疫疫苗过程中配合注射禽流感抗体,禽流感的抗体效价呈先上升然后下降再上升的变化趋势,而A组未注射禽流感抗体的鸡,禽流感抗体效价则呈先下降然后上升的变化趋势;商品肉鸡各免疫组禽流感抗体效价均呈先下降然后上升的变化趋势,疫苗免疫后的前期注射禽流感抗体组的禽流感抗体效价相对高些。说明商品蛋鸡免疫新流二联灭活疫苗时配合注射禽流感抗体对机体的禽流感抗体短期提升效果较明显,可提高禽流感疫苗的免疫效果;而在商品肉鸡上配合注射禽流感抗体对机体的禽流感抗体提升效果不明显。     

不同白油佐剂制备的H9N2灭活疫苗在SPF鸡上的免疫效果初试验

为了比较不同厂家的注射用矿物白油佐剂的免疫效果,试验采用3个不同黏度的国外白油样品,按照《中华人民共和国兽药典》进行注射用白油质量检验、制备3批H9N2油乳剂灭活疫苗,分别以0.3ml/只剂量,胸部肌肉注射接种28日龄SPF鸡,接种后14d、21d、28d、35d、42d分别进行疫苗的药物残留吸收检查和血清抗体效价检测。结果表明:3种佐剂疫苗的安全性、稳定性均良好;应用WG40白油佐剂的灭活疫苗,免疫SPF鸡产生的H9N2禽流感HI抗体水平优于其它两种佐剂,免疫3周后检测到的H9N2禽流感抗体水平均合格,WG40确定为最佳白油佐剂。     

鸡新城疫-禽流感二联灭活疫苗免疫不同日龄商品肉鸡的效果比较

使用鸡新城疫-禽流感（H9N2 HP株）二联灭活疫苗分别免疫3、7、14日龄三组商品肉鸡各40羽,同时设一组空白对照组。各免疫组及对照组于3、7、14、21、28、35、42日龄采血检测新城疫、禽流感抗体,于21、28、35日龄进行禽流感病毒攻毒,对比不同日龄免疫组的抗体消涨情况及不同日龄禽流感攻毒结果。发现对照组随鸡日龄增加,新城疫与禽流感抗体逐渐下降,在42日龄时下降至0,而不同免疫组新城疫与禽流感抗体均先下降,21日龄左右开始上升,至35日龄新城疫与禽流感抗体升至6log2以上。3日龄免疫组的禽流感免疫保护效果最好,21、28、35日龄时禽流感强毒攻毒保护率均达100%;7日龄免疫组在21、35日龄时禽流感强毒攻毒保护率均达100%,28日龄时禽流感强毒攻毒保护率达70%;14日龄免疫组在28、35日龄时禽流感强毒攻毒保护率均达100%,21日龄时禽流感强毒攻毒保护率只达30%。试验表明,商品肉鸡选择3日龄免疫鸡新城疫-禽流感（H9N2 HP株）二联灭活疫苗时禽流感免疫保护效果最好,采用3日龄免疫程序可以提高新城疫与禽流感的免疫保护效果,减少养殖业的经济损失。     

CAV与REV共感染SPF鸡对疫苗免疫反应的抑制作用

用1日龄SPF鸡人工感染鸡贫血病毒(CAV)和禽网状内皮增生病病毒(REV),探讨病毒感染对鸡体疫苗免疫反应的影响。结果表明,在用禽流感病毒(AIV,H5和H9)疫苗免疫后,CAV与REV单独感染均显著抑制了鸡体对H5和H9亚型禽流感病毒灭活疫苗的HI抗体反应,在CAV与REV共感染后,这种抑制作用更为明显。CAV单独感染后鸡体对新城疫病毒(NDV)和传染性法氏囊病病毒(IBDV)疫苗的免疫反应受到抑制,但与对照组在统计学上的差异不显著,然而,CAV可以显著加重REV感染对鸡体在NDV和IBDV疫苗免疫后抗体反应的抑制作用。从而证实CAV与REV共感染在疫苗免疫抑制上有协同作用。     

不同新城疫弱毒苗对新城疫病毒强毒的免疫保护试验

用NDV的LaSota株、VG/GA 株、VH 株、PHY LMV 42株及Clone 30株弱毒疫苗免疫SPF鸡后 ,通过对雏鸡免疫后的血清抗体监测表明 ,4种弱毒疫苗激发雏鸡的抗新城疫病毒抗体滴度在 7log2水平以下 ,且差异不显著。通过以上 4种新城疫弱毒疫苗对新城疫病毒东台强毒株的免疫保护试验表明 :至少单独使用弱毒疫苗 ,不能对东台地区流行的新城疫病毒强毒株提供有效保护 ,保护率在 60 %～ 74%     

新城疫病毒接种鸡血清中IgM、IgG的动态变化

将１６只ＳＰＦ鸡分成４组，每组４只，分别接种新城疫油乳剂苗，新城疫、传染性支气管炎、传染性法氏囊病三联油乳剂苗，ＬａＳｏｔａ弱毒苗和Ｍｕｋｔｅｓｗｅｒ苗。接种后每隔２ｄ采血１次，用ＥＬＩＳＡ测定新城疫特异性ＩｇＭ和ＩｇＧ抗体。结果：油乳剂灭活苗接种组均无特异性ＩｇＭ抗体出现，特异性ＩｇＧ抗体高峰期出现在接种后２２ｄ，ＬａＳｏｔａ弱毒苗和Ｍｕｋｔｅｓｗｅｒ苗接种组均有特异性ＩｇＭ抗体出现，高峰期为接种后第９ｄ。各接种组经强毒攻击后，均出现ＩｇＭ反应，ＩｂＧ呈典型的回忆反应。进一步试验用ＬａＳｏｔａ灭活苗经肌肉、静脉接种和加氢氧化铝胶佐剂后肌肉接种，经测定，接种鸡均无或仅有很低水平的特异性ＩｇＭ抗体产生。     

禽流感H9亚型流行毒株交叉免疫保护试验

采用北京市农林科学院畜牧兽医研究所1998年-2008年在北京及河北省分离的4株禽流感病毒H9亚型流行毒株,分别制备不同分离毒株灭活疫苗,免疫SPF鸡,进行交叉免疫保护试验。结果表明,用4个不同时期的分离毒株所制备出的灭活疫苗免疫鸡后,各免疫组鸡禽流感(H9亚型)的HI抗体效价均明显上升,所诱导产生的HI抗体效价基本相同;不同时期分离毒株大多产生了较好的交叉保护力。用1998年、2004年及2006年分离的流行毒株制备出的灭活疫苗能够保护2008年流行毒株的攻击。     

Reduced serologic response to Newcastle disease virus in broiler chickens exposed to a Chinese field strain of subgroup J avian leukosis virus

In this study, a Chinese field strain of subgroup J avian leukosis virus (ALV-J), NX0101, was studied for its immunosuppressive effects in both commercial broilers and SPF white Leghorn chickens infected at 1 day of age. Our data demonstrated that NX0101 induced much more significant body and immune organ weight loss in the infected commercial broiler chickens in an earlier age than that in the SPF white Leghorn chickens. At the same time antibody responses to vaccinations of Newcastle disease virus (NDV) and infectious bursa disease virus (IBDV) in the NX0101-infected chickens were also evaluated and compared between the commercial broiler chickens and the SPF white Leghorn chickens. Compared with the control group of chickens, the hemagglutination inhibition (HI) antibody response to NDV vaccines was significantly reduced in the NX0101-infected commercial broiler chickens from as early as 20 days after vaccination. However, no significant difference in HI antibody response was seen when HI titers reached their peaks in the NX0101-inoculated and control SPF white Leghorn chickens, except it declined significantly faster in infected birds. Neither of these two types of chickens showed significant decrease of antibody response to IBDV vaccination. Herein, we conclude that this NX0101 strain of ALV-J could selectively suppress humoral immune reactions to NDV, especially in broilers. But challenge experiments were not conducted and, therefore, it cannot be known if decreased antibody levels correlated with decreased protection against NDV in this case.     

Bilateral effects of vaccination against infectious bursal disease and Newcastle disease in specific-pathogen-free layers and commercial broiler chickens

Different infectious bursal disease virus (IBDV) live vaccines (intermediate, intermediate plus) were compared for their immunosuppressive abilities in specific-pathogen-free (SPF) layer-type chickens or commercial broilers. The Newcastle disease virus (NDV) vaccination model was applied to determine not only IBDV-induced immunosuppression but also bilateral effects between IBDV and NDV. None of the IBDV vaccines abrogated NDV vaccine-induced protection. All NDV-vaccinated SPF layers and broilers were protected against NDV challenge independent of circulating NDV antibody levels. Sustained suppression of NDV antibody development was observed in SPF layers, which had received the intermediate plus IBDV vaccine. We observed a temporary suppression of NDV antibody development in broilers vaccinated with one of the intermediate, as well as the intermediate plus, IBDV vaccines. Different genetic backgrounds, ages, and residual maternal antibodies might have influenced the pathogenesis of IBDV in the different types of chickens. Temporary suppression of NDV antibody response in broilers was only seen if the NDV vaccine was administered before and not, as it was speculated previously, at the time the peak of IBDV-induced bursa lesions was detected. For the first time, we have demonstrated that the NDV vaccine had an interfering effect with the pathogenesis of the intermediate as well as the intermediate plus IBDV vaccine. NDV vaccination enhanced the incidence of IBDV bursa lesions and IBDV antibody development. This observation indicates that this bilateral effect of an IBDV and NDV vaccination should be considered in the field and could have consequences for the performance of broiler flocks.     

Improved protection from velogenic Newcastle disease virus challenge following multiple immunizations with plasmid DNA encoding for F and HN genes

Specific-pathogen free (SPF) chickens were inoculated with the plasmid constructs encoding the fusion (F) and haemagglutinin-neuraminidase (HN) glycoproteins of Newcastle disease virus (NDV), either individually or in combination and challenged with velogenic NDV. The antibody level against NDV was measured using commercial enzyme linked immunosorbent assay (ELISA). In the first immunization regimen, SPF chickens inoculated twice with NDV-F or NDV-HN constructs elicited antibody responses 1 week after the second injection. However, the levels of the antibody were low and did not confer significant protection from the lethal challenge. In addition, administration of the plasmid constructs with Freund's adjuvant did not improve the level of protection. In the second immunization regimen, chickens inoculated twice with the plasmid constructs emulsified with Freund's adjuvant induced significant antibody titers after the third injection. Three out of nine (33.3%) chickens vaccinated with pEGFP-HN, five of ten (50.0%) chickens vaccinated with pEGFP-F and nine of ten (90.0%) chickens vaccinated with combined pEGFP-F and pEGFP-HN were protected from the challenge. No significant differences in the levels of protection were observed when the chickens were vaccinated with linearized pEGFP-F. The results suggested that more than two injections with both F and HN encoding plasmid DNA were required to induce higher level of antibodies for protection against velogenic NDV in chickens.     

鸡新城疫、传染性支气管炎、禽流感(H9亚型)三联灭活疫苗对禽流感H9亚型流行株攻毒的保护作用

为了监测鸡新城疫、传染性支气管炎、禽流感(H9亚型)三联灭活疫苗(LaSota株+M41株+SS/94株)对H9亚型禽流感病毒流行毒株的免疫保护效果,采用H9亚型禽流感病毒SS/94株及2009—2010年现地分离的3株H9亚型禽流感病毒对已免疫上述三联灭活苗的SPF鸡进行攻毒试验。结果显示,试验鸡以0.3 mL/只的剂量免疫三联灭活苗后21 d,其H9亚型禽流感病毒的HI抗体效价可达8～11log2,此抗体水平可抵抗2×106EID50的H9亚型禽流感病毒SS/94株、BLCN09株、WDZ09株、YT10株的攻击,攻毒保护率均达90%(9/10)以上。可见,以SS/94株作为禽流感疫苗抗原制备的三联灭活苗具有良好的免疫原性,能使免疫鸡抵抗2009—2010年期间现地分离的多株H9亚型禽流感病毒的攻击。