猪流感H1、H3亚型灭活疫苗

猪流感(SI)是由猪流感病毒(SIV)引起的一种急性、高度接触传染性的群发性猪呼吸道疾病,是猪的主要免疫抑制病之一;临床以突发、高热、咳嗽、呼吸困难、衰竭为特征,发病率高达100%,该病一旦发生,传播迅速,可直接引起患猪死亡,引起妊娠母猪流产或产弱仔,并使患猪生产性能下降,肉料比降低,在集约化养猪场中普遍存在,难以根除,对养猪业危害极大.H1N1和H3N2的协同流行,使疫情加重,同时极易协同发生猪呼吸-繁殖障碍综合征、猪伪狂犬病、猪呼吸道冠状病毒、猪传染性胸膜肺炎、猪传染性萎缩性鼻炎、猪巴氏杆菌病、猪2型链球菌及猪肺炎支原体的感染,猪流感症状减缓或消除,猪体表现出猪呼吸-繁殖障碍综合征、猪肺炎支原体等典型症状,使病情复杂而反复,直接影响猪群健康状态和猪的质量,经济损失无法估量.……     

猪流感二价灭活疫苗(H1N1 LN株+H3N2 HLJ株)田间应用效果分析

猪流感(SIV)是由A型流感病毒引起的一种猪的急性呼吸道传染病,发病急、传染性快、发病率高,虽然单纯的猪流感致死率不高,但是其导致的继发感染和隐性损失较大,给猪场经济效益带来严重损失。在我国,保守统计1000头存栏肥猪发生一次猪流感所带来的经济损失每头猪至少增加50~80元饲养成本(欧洲约7英镑)。疫苗免疫是防控猪流感的重要手段,猪流感二价灭活疫苗(H1N1 LN株+H3N2 HLJ株)(以下简称“华感健”)自上市以来,深受国内猪场尤其是规模猪场的青睐,100万头份已在临床猪场应用,现将某集团部分规模场华感健使用效果作总结分析,供读者参考。     

猪流感(H3N2亚型)油乳剂灭活疫苗的免疫及攻毒试验

用不同剂量的猪流感H3N2亚型油乳剂灭活疫苗免疫15头断奶仔猪,每组5头,四周后二免。另外3头为非免疫攻毒对照组。首免后第10周用同源病毒攻毒,分别在免疫前及免疫后2、3、4、6、8、10、11周采血,分离血清,用HI试验检测其抗体滴度。攻毒后通过免疫猪和非免疫攻毒对照猪临床、病理变化及病毒分离等方面的比较,评价疫苗的保护效果。结果中、高剂量组的抗体滴度明显高于低剂量组;免疫组和对照组攻毒前后体温无显著差异(P>0.05),免疫组病理保护明显好于非免疫攻毒对照组;鼻液和肺中的病毒分离率比较,免疫组明显低于非免疫攻毒对照组。本研究表明,用该疫苗免疫后猪对同亚型的病毒攻击有一定的保护作用。     

H_5N_1亚型禽流感灭活疫苗对黄羽肉鸡的免疫效果研究

为了准确掌握禽流感疫苗(H_5N_1)的抗体消长规律,以不同剂量、不同途径免疫母源抗体消失的黄羽肉雏鸡,定期测定抗体效价。第4周各组HI抗体效价达到最高,均值分别为第一组9.7log2、第二组9.8log2、第三组9.5log2、第四组4.6log2,各组抗体效价从第6周开始下降,第8周以后下降相对较缓慢。18周内能够维持较高的抗体水平,20周以后抗体效价均值降低到4log2以下。各注射免疫组抗体合格率在4～10周内维持较高水平,第10周以后缓慢下降,18周内维持在70%以上,之后下降到70%以下。饮水免疫组自始至终不合格。     

H_5N_1亚型禽流感病毒研究进展

自1997年香港发现首例人感染H_5N_1禽流感病毒以来,不断有人禽流感病例报道,到目前为止,全球共有15个国家和地区的393人感染,其中248人死亡,死亡率63%。中国从03年至今有31人感染禽流感,其中21人死亡。因此它可能成为新一轮流感大流行的病原,引起了全球的高度关注,目前WHO对其已是3级预警。人类对流感病毒的认识既了解又不十分清楚,尤其是其致病性仍有很多不清楚的问题,这是由于流感病毒的致病性取决于病毒毒力和受感染宿主等诸因素,影响因素比较复杂之故。本文就目前H_5N_1禽流感病毒来源,跨越物种传播的机制,致病力决定因素及人间传播能力等几个关键的基础问题研究进展进行综述。     

重组禽流感病毒(H_5+H_7)二价灭活疫苗免疫效果评估

为比较来源不同厂家的重组禽流感病毒(H_5+H_7)二价灭活疫苗在哈伯德父母代肉种鸡上的应用效果,通过颈部皮下注射21日龄和50日龄的哈伯德父母代肉种鸡,免疫后1周、2周、3周采血并分别检测H_5(Re-8)、H_7(Re-1)的抗体滴度,同时比较其抗体消长规律。试验结果表明,不同厂家疫苗在H_5亚型的免疫效果应答上存在差异显著,在加强免疫后的免疫应答也差异显著;在H_7亚型的免疫应答上差异显著,加强免疫后免疫效果差异不显著。     

H_9N_2亚型禽流感的综合防控

<正>1H9N2亚型禽流感的发病特点年龄变化:雏鸡、青年鸡易感、症状严重,大鸡发病轻微;减蛋变化:免疫鸡仍然会减蛋,但程度较轻。季节变化:冬季寒冷时严重,夏季炎热时较轻。免疫变化:未免疫鸡严重,免疫一次但抗体未上来较轻。肉鸡变化:颈胸部皮下发绀,广泛性卵黄性炎变。发病差异较大:有流泪、肿眼、流鼻液、     

H_9N_2亚型禽流感的综合防治

<正>禽流感目前仍是危害我国养禽业的重要传染性疾病。H9N2亚型禽流感呈地方性流行、持续存在,严重危害我国养禽业的发展。造成其流行的原因很多,疫源地的传染源根除十分不易,疫情隐患长期存在;市场开放、流通频繁、检疫工作滞后等给流行     

科学认识H_5N_1亚型高致病性禽流感

AIV按其毒力和致病性可分为高致病性禽流感病毒(HPAIV)和低致病性禽流感病毒(LPAIV).所谓的高致病性是指高感染性和高病原性,高感染性体现在病毒经一定途径侵入机体后能在机体各组织器官内快速有效的复制和在不同个体间进行快速有效地传播,并能在极短的时间内(一般为48 h)导致全群鸡发病死亡:高病原性是指少数的病毒粒子进入到机体后可引起全身感染,导致多系统、器官功能衰竭,最终导致死亡.     

重组禽流感病毒H_5亚型二价灭活苗(H_5N_1,Re-5株+Re-4株)的免疫效果评价

为评价H5N1高致病性禽流感二价灭活苗（H5N1,Re-5株＋Re-4株）的免疫效果。选择健康无禽流感免疫史的62日龄肉鸡20羽作为保护期外组（Ⅰ组）;选择健康并有2次H5N1亚型Re-5株疫苗免疫史的110日龄肉鸡19羽作为保护期内组（Ⅱ组）。每羽胸肌注射二价苗0.5 mL。试验证实,重组禽流感病毒H5亚型二价灭活疫苗（H5N1,Re-5株＋Re-4株）免疫注射后,未见临床异常反应,一次免疫注射后即可达到群体合格率70%以上。     

规模化猪场H1亚型猪流感油乳剂灭活疫苗免疫的抗体变化动态

猪流感(Swine influenza,SI)是由正粘病毒科A型流感病毒引起的一种猪的急性、热性、高度接触性呼吸道传染病,临床上以高热、精神沉郁、食欲下降、呼吸困难为特点,可导致猪只生产性能下降,料肉比上升,增重减缓。猪流感常导致猪繁殖与呼吸障碍综合征、传染性胸膜肺炎、猪链球菌等     

Failure of protection and enhanced pneumonia with a US H1N2 swine influenza virus in pigs vaccinated with an inactivated classical swine H1N1 vaccine

Two US swine influenza virus (SIV) isolates, A/Swine/Iowa/15/1930 H1N1 (IA30) and A/Swine/Minnesota/00194/2003 H1N2 (MN03), were evaluated in an in vivo vaccination and challenge model. Inactivated vaccines were prepared from each isolate and used to immunize conventional pigs, followed by challenge with homologous or heterologous virus. Both inactivated vaccines provided complete protection against homologous challenge. However, the IA30 vaccine failed to protect against the heterologous MN03 challenge. Three of the nine pigs in this group had substantially greater percentages of lung lesions, suggesting the vaccine potentiated the pneumonia. In contrast, priming with live IA30 virus provided protection from nasal shedding and virus replication in the lung in MN03 challenged pigs. These data indicate that divergent viruses that did not cross-react serologically did not provide complete cross-protection when used in inactivated vaccines against heterologous challenge and may have enhanced disease. In addition, live virus infection conferred protection against heterologous challenge.     

种鸡禽流感(H5+H9)二价灭活疫苗免疫程序的研究

本研究设计不同的免疫程序,用禽流感(H5+H9)二价灭活疫苗(H5N1 Re-1+H9N2 Re-2株)免疫黄羽种鸡,通过对H5亚型和H9亚型禽流感HI抗体滴度监测,探讨H5亚型和H9亚型禽流感HI抗体消长规律及禽流感(H5+H9)二价灭活疫苗的免疫程序.结果表明,用禽流感二价灭活疫苗免疫黄羽种鸡后,H5亚型和H9亚型禽流感HI抗体的消长规律基本同步,其抗体滴度阶段性峰值出现在免疫后的第21~28天.根据试验结果,建议用禽流感二价灭活疫苗免疫黄羽种鸡的免疫程序设为:首免(14 d),0.3 mL/只;二免(56 d),0.5 mL/只;三免(119 d或开产前4周),0.5 mL/只.     

Comparative study of pandemic (H1N1) 2009, swine H1N1, and avian H3N2 influenza viral infections in quails

Quail has been proposed to be an intermediate host of influenza A viruses. However, information on the susceptibility and pathogenicity of pandemic H1N1 2009 (pH1N1) and swine influenza viruses in quails is limited. In this study, the pathogenicity, virus shedding, and transmission characteristics of pH1N1, swine H1N1 (swH1N1), and avian H3N2 (dkH3N2) influenza viruses in quails was examined. Three groups of 15 quails were inoculated with each virus and evaluated for clinical signs, virus shedding and transmission, pathological changes, and serological responses. None of the 75 inoculated (n = 45), contact exposed (n = 15), or negative control (n = 15) quails developed any clinical signs. In contrast to the low virus shedding titers observed from the swH1N1-inoculated quails, birds inoculated with dkH3N2 and pH1N1 shed relatively high titers of virus predominantly from the respiratory tract until 5 and 7 DPI, respectively, that were rarely transmitted to the contact quails. Gross and histopathological lesions were observed in the respiratory and intestinal tracts of quail inoculated with either pH1N1 or dkH3N2, indicating that these viruses were more pathogenic than swH1N1. Sero-conversions were detected 7 DPI in two out of five pH1N1-inoculated quails, three out of five quails inoculated with swH1N1, and four out of five swH1N1-infected contact birds. Taken together, this study demonstrated that quails were more susceptible to infection with pH1N1 and dkH3N2 than swH1N1.     

猪流感病毒H1N1、H1N2和H3N2亚型多重RT-PCR诊断方法的建立

对我国分离到的猪流感病毒和GenBank数据库中已有的猪流感病毒H1N1、H1N2和H3N2亚型毒株的HA、NA基因核苷酸序列进行分析,分别选出各个病毒亚型HA和NA基因中高度保守且特异的核苷酸区域,设计扩增猪流感病毒H1和H3、N1和N2亚型的2套多重PCR特异性引物,建立了猪流感H1N1、H1N2和H3N2亚型病毒多重RT-PCR诊断方法。采用该方法对H1N1、H1N2、H3N2亚型猪流感病毒标准参考株进行RT-PCR检测,结果均呈阳性,对扩增得到的片段进行序列测定和BLAST比较,表明为目的基因片段。其它几种常见猪病病毒和其它亚型猪流感病毒的RT-PCR扩增结果都呈阴性。对107EID50/0.1mL病毒进行稀释,提取RNA进行敏感性试验,RT-PCR最少可检测到102EID50的病毒量核酸。对40份阳性临床样品的检测结果是H1N1、H1N2和H3N2亚型分别为16份、1份和20份,其它3份样品同时含有H1N1和H3N2亚型猪流感病毒,和鸡胚分离病毒结果100%一致。试验证明建立的猪流感病毒H1N1、H1N2和H3N2亚型多重RT-PCR诊断方法是一种特异敏感的诊断方法,可用于临床样品的早期快速诊断和分型。     

Protective efficacy of a high-growth reassortant swine H3N2 inactivated vaccine constructed by reverse genetic manipulation

Novel reassortant H3N2 swine influenza viruses (SwIV) with the matrix gene from the 2009 H1N1 pandemic virus have been isolated in many countries as well as during outbreaks in multiple states in the United States, indicating that H3N2 SwIV might be a potential threat to public health. Since southern China is the world''s largest producer of pigs, efficient vaccines should be developed to prevent pigs from acquiring H3N2 subtype SwIV infections, and thus limit the possibility of SwIV infection at agricultural fairs. In this study, a high-growth reassortant virus (GD/PR8) was generated by plasmid-based reverse genetics and tested as a candidate inactivated vaccine. The protective efficacy of this vaccine was evaluated in mice by challenging them with another H3N2 SwIV isolate [A/Swine/Heilongjiang/1/05 (H3N2) (HLJ/05)]. Prime and booster inoculation with GD/PR8 vaccine yielded high-titer serum hemagglutination inhibiting antibodies and IgG antibodies. Complete protection of mice against H3N2 SwIV was observed, with significantly reduced lung lesion and viral loads in vaccine-inoculated mice relative to mock-vaccinated controls. These results suggest that the GD/PR8 vaccine may serve as a promising candidate for rapid intervention of H3N2 SwIV outbreaks in China.     

Reassortant H1N1 influenza virus vaccines protect pigs against pandemic H1N1 influenza virus and H1N2 swine influenza virus challenge

Influenza A (H1N1) virus has caused human influenza outbreaks in a worldwide pandemic since April 2009. Pigs have been found to be susceptible to this influenza virus under experimental and natural conditions, raising concern about their potential role in the pandemic spread of the virus. In this study, we generated a high-growth reassortant virus (SC/PR8) that contains the hemagglutinin (HA) and neuraminidase (NA) genes from a novel H1N1 isolate, A/Sichuan/1/2009 (SC/09), and six internal genes from A/Puerto Rico/8/34 (PR8) virus, by genetic reassortment. The immunogenicity and protective efficacy of this reassortant virus were evaluated at different doses in a challenge model using a homologous SC/09 or heterologous A/Swine/Guangdong/1/06(H1N2) virus (GD/06). Two doses of SC/PR8 virus vaccine elicited high-titer serum hemagglutination inhibiting (HI) antibodies specific for the 2009 H1N1 virus and conferred complete protection against challenge with either SC/09 or GD/06 virus, with reduced lung lesions and viral shedding in vaccine-inoculated animals compared with non-vaccinated control animals. These results indicated for the first time that a high-growth SC/PR8 reassortant H1N1 virus exhibits properties that are desirable to be a promising vaccine candidate for use in swine in the event of a pandemic H1N1 influenza.     

抗H3N2亚型猪流感病毒单克隆抗体的制备与鉴定

采用纯化的H3N2亚型猪流感病毒(SIV)尿囊液作为免疫原免疫6～8周龄Balb/c小鼠,取免疫小鼠脾细胞与骨髓瘤细胞(SP2/0)融合,用间接ELISA方法筛选分泌抗SIV-H3N2的阳性细胞株,经克隆获得7株亲和力较高的杂交瘤细胞株,分别命名为1C9、2C5、2F10、3D3、4E8、5C7、5D12,用其制备的腹水ELISA效价可达1×106。通过抗体亚型测定,间接免疫荧光试验及免疫印迹试验分析鉴定,该7株单抗均为抗H3N2亚型SIV的特异性单克隆抗体,而且与其他亚型猪流感病毒、猪细小病毒、猪繁殖与呼吸综合征病毒、猪圆环病毒和猪瘟病毒等均无交叉反应,为H3N2亚型SIV的鉴别诊断奠定了基础。     

猪流感病毒分离株A/swine/Shanghai/3/2014(H1N1)分子特性研究

采用套式PCR检测方法,结合鸡胚分离鉴定,从20份患呼吸道疾病猪的鼻咽拭子样品中分离到1株流感病毒。经亚型鉴定及全基因组序列分析,证实该分离株为H1N1流感病毒,命名为A/swine/Shanghai/3/2014(H1N1)。遗传进化分析表明该分离株与类禽猪流感病毒(Avian-Like H1N1)相似性最高。蛋白序列分析发现,该分离株具有低致病性流感病毒特征,即其HA蛋白的裂解位点为PSIQSR↓GLFGAI。此外,该基因中有7个潜在的糖基化位点,受体结合位点为108(Y)、148~152(GVTAA)、167(W)、197(H)、204~212(DQQ SLYQNA)和238~243(RDQEGR);其中225~228EQAG显示该分离株具有结合SAα2,6Gal受体的能力,证明该分离株具有感染哺乳动物的能力。同时PB2蛋白的627E、701N及NS蛋白的92D位点均证明了该分离株的低致病性和感染哺乳动物的能力。