鸡传染性法氏囊炎(IBD)K株活疫苗现地蛋鸡免疫试验

鸡传染性法氏囊炎是由呼肠弧病毒引起的一种以破坏鸡免疫器官法氏囊为主的急性传染病。为了更好地防制本病 ,我们从日本国引进了新的法氏囊炎Ｋ株活疫苗种毒 ,在ＧＭＰ车间生产条件下 ,应用ＳＰＦ种蛋 ,生产出 2 - 8℃保存的活疫苗 ,并对其进行了现地蛋鸡免疫试验。1　材料与方法1 .1　试验动物及疫苗试验鸡 :天津市靳连登养鸡场饲养的海塞克斯商品蛋鸡1 6 0 0 0羽 ,试验组 (Ａ组 ) 80 0 0羽 ;对照组 (Ｂ组 ) 80 0 0羽。使用疫苗 :Ａ组用黑龙江化血研生物技术有限公司生产的ＩＢＤＫ株活疫苗 ;对照组使用国内某厂生产的ＩＢＤＢ87株活疫苗。…     

鸡传染性法氏囊活疫苗（K株）免疫肉鸡效果

1　材料和方法1．1　试验鸡群　从汤阴县肉种鸡场购进AA肉仔鸡1 200只。1．2　供试疫苗　黑龙江化血研生物技术有限公司生产，批号为98065，每瓶1 000羽份，含IBD病毒每羽份TCID50104．0以上。1．3　试验药品　IBD琼扩抗原及标准阳性血清购自中国农业科学院哈尔滨兽医研究所。1．4　试验方法　随机把鸡群平均分成A、B、C三组，A、B为试验组，饲养在2号舍，C组为对照组，饲养在5号舍，每组各400只。试验鸡在2、7、14、19、21日龄随机取样10～20只鸡采血分离血清，用琼脂扩散试验测定母源抗体。A组试验鸡于14日龄和21日龄分别用一个剂…     

鸡传染性法氏囊病二价活疫苗与国外囊病活疫苗免疫效力比较试验

鸡传染性法氏囊病（ＩＢＤ）是一种引起３～１２周龄雏鸡和青年鸡的高度接触性病毒传染病,疫苗免疫接种仍是防制该病的最主要手段,但近年来,鸡传染性法氏囊病病毒血清亚型或变异株和超强毒株的出现,使常规的Ｉ型疫苗常常造成免疫失败［２,３,４］,针对这种情况,我...     

三种鸡传染性法氏囊病活疫苗免疫效力的比较研究

试验用3种不同亚型的鸡传染性法氏囊病（IBD）疫苗毒株制备单价、双价及三价活疫苗。将3种苗分别免疫10－14日龄的SPF鸡，于免疫后1－4周内用法氏囊标准强毒株攻击；攻毒后第3d、14d观察法氏囊病理变化并测定法氏囊重／体重比值；同时检测免疫鸡血清中和抗体水平。试验结果表明，双价及三价活疫苗有明显高的攻毒保护率；血清中和抗体产生早，抗体水平高。     

商品化鸡传染性法氏囊病活疫苗的免疫效果及其对鸡法氏囊的损伤研究

用市售的 3种中等毒力鸡传染性法氏囊病（infectious bursal disease, IBD）活疫苗分别免疫SPF鸡,9日龄首免,22日龄二免,并于二免后第2、9、21天,每组随机抽取5只,抽血测定IBD抗体,同时检查法氏囊的损伤情况。结果表明,3种中等毒力的IBD活疫苗对鸡法氏囊均会造成一定的损伤,但损伤程度有差异,且这种损伤在一定时期内可以恢复。3种中等毒力IBD活疫苗刺激鸡产生抗体的水平也存在差异。     

鸡传染性法氏囊病细胞活疫苗的研制

控制鸡传染性法氏囊病(IBD)的主要方法是疫苗接种，本研究在已有鸡胚苗的基础上，研制了法氏囊细胞活疫苗。     

甲硝唑对鸡传染性法氏囊病活疫苗免疫效果的影响

本研究观察了药物对传染性法氏囊病（IBD）活疫苗初次免疫和二次免疫的影响，结果显示高抗传染性法氏囊病病毒（IBDV）母源抗体雏鸡IBD活疫苗初次免疫前应用10－100毫克／千克甲硝唑和10毫克／千克左旋咪唑，在免疫鸡血清抗IBDV抗体水平明显下降，甲硝唑用药鸡疫苗二次免疫后，血清抗IBDV抗体滴度明显高于未用药对照组。10毫克／千克左旋咪唑给药组疫苗二次免疫后鸡血清抗IBDV抗体滴度与未用药对照组无明显差别。     

鸡传染性法氏囊病三价与单价活疫苗的效力比较试验

鸡传染性法氏囊病(IBD)是3～12周龄鸡的一种高度接触性病毒传染病，会造成鸡的主要免疫器官——法氏囊损伤，导致机体的免疫抑制，使病鸡对其它疾病的易感性增加，对其它疫苗免疫的应答能力下降，给养鸡业造成严重危害。近年来，鸡法氏囊病病毒血清亚型或变异株和超强毒株的出现，使该病又出现了一些新的流行特点。传统的标准Ⅰ型弱     

鸡脾转移因子对鸡新城疫、传染性法氏囊病活疫苗免疫效果的影响

鸡脾转移因子（TF）与鸡新城疫活疫苗和法氏囊活疫苗配合使用，免疫雏鸡。结果显示，在ND-HI抗体较低时，TF对新城疫活疫苗有免疫增强作用，而在母源抗体水平较高时，免疫增强作用不明显。本次试验中，TF对法氏囊活疫苗未显示明显的免疫增强作用。     

用不同方法进行鸡传染性法氏囊病活疫苗的效力检验

鸡传染性法氏囊病活疫苗在对鸡的传染性法氏囊病免疫上广泛应用 ,其特点是使用方便 ,免疫效果好。但在其效力检验上 ,我国目前使用的方法与国外一些国家使用的方法存在着差异。为此我们对鸡传染性法氏囊病活疫苗进行了效力检验对比试验 ,现报告如下。1　试验材料ＳＰＦ鸡胚 :由黑龙江化血研生物技术有限公司ＳＰＦ鸡场提供ＳＰＦ种蛋 ,本实验室自行孵化。鸡胚成纤维细胞 :由ＳＰＦ胚自行制备的鸡胚成纤维细胞(ＣＥＦ)。鸡传染性法氏囊病活疫苗 :由黑龙江省生物制品一厂提供(批号 :2 0 0 0 5 2 ) ,每瓶 10 0 0羽份。由某合资公司提供 (批号 :…     

Attenuation of a strain of rinderpest virus: potential homologous live vaccine

Peste des petits ruminants (PPR) is a highly contagious disease of small ruminants frequently associated with severe mortality in these hosts. In countries where it occurs, PPR represents an important constraint to the improved productivity of sheep and goats. Until now the only way to combat this plague has been the use of heterologous rinderpest vaccine; all attempts to develop a homologous vaccine have ended in failure. The present communication describes the attenuation of the Nigerian strain PPRV Nig 75/1 by serial passage in Vero cells. The avirulent virus obtained has the same characteristics as Plowright and Ferris' rinderpest vaccine. The virus is advanced as a potential homologous vaccine against PPR.     

Evaluation of a modified live virus type-1a bovine viral diarrhea virus vaccine (Singer strain) against a type-2 (strain 890) challenge

Both type-1 and type-2 bovine viral diarrhea virus (BVDV) infections are responsible for major losses in the cattle industry. However, several commercial BVDV vaccines contain only a type-1 strain. A vaccine trial was conducted to evaluate the efficacy of BVDV type-1 (Singer strain; BVDV-1) vaccine for protecting calves challenged with virulent BVDV type-2 (890 strain; BVDV-2). Thirty-eight BVDV-negative calves were randomly allocated to four groups. One group was treated with a modified live virus (MLV) BVDV-1 vaccine by i.m. injection and another group was treated with the same vaccine by s.c. injection. Two groups served as nonvaccinated controls (one i.m. and one s.c.). Twenty-eight days following vaccination, the calves were challenged with BVDV-2 and monitored for 21 days. Clinical scores and body temperatures of vaccinated calves were significantly (P<.05) lower than for controls on several days, and peak differences occurred 8 days after challenge. The control calves had significantly (P<.05) lower leukocyte counts 3 through 8 days after challenge; leukocyte counts for vaccinated animals did not decline significantly from prechallenge levels. There were no differences in protection between the i.m. and s.c. routes of vaccination. The study demonstrated satisfactory cross protection of the BVDV-1 vaccine against BVDV-2 challenge.     

Retrospective genome analysis of a live vaccine strain of bovine viral diarrhea virus

A live bovine viral diarrhea (BVDV) vaccine, marketed as a derivate of the Oregon C24V strain, was used between the end of the 1960s and the beginning of the 1990s in Central Europe. Since laboratory investigations of mucosal disease cases in vaccinated animals suggested recombinations between the vaccine and wild type variants of BVDV, and recombinational nucleotide sequences seemed distinct from BVDV Oregon C24V, the aim of the present retrospective study was to analyze the genomes of pre-registration (termed here BVDV-Xpre) and of marketed (BVDV-X) batches of the vaccine. The results of the complete genome analysis of BVDV-Xpre confirmed that the original virus strain used at the start of the vaccine production was Oregon C24V. Surprisingly, the analysis of the complete nucleotide sequence of the BVDV-X marketed vaccine revealed that this strain belongs to the BVDV 1b subgroup, with a 93.7% nucleotide sequence homology to BVDV reference strain Osloss. The homology to BVDV Oregon C24V was significantly lower (77.4%), and a thorough sequence scanning showed that the genome of BVDV-X had not derived from Oregon C24V. These data indicate the very likely scenario that a strain different to Oregon C24V was picked up during the in vitro or in vivo passages for vaccine development. Despite of the virus-switch, the BVDV-X vaccine continuously maintained its innocuity and efficacy, as proven by the regular quality testing data, and the presence of the foreign virus remained unnoticed over many years. The results of this work emphasize that the contamination of commercially available live vaccines with exogenous BVDV strains is a real risk factor, and a unequivocal analysis, including molecular methods, is needed to verify their authenticity.     

Efficacy of Fostera PRRS modified live virus vaccine against a Canadian heterologous virulent field strain of porcine reproductive and respiratory syndrome virus

Vaccination is a useful option to control infection with porcine reproductive and respiratory syndrome virus (PRRSV), and several modified live-PRRSV vaccines have been developed. These vaccines have shown some efficacy in reducing the incidence and severity of clinical disease as well as the duration of viremia and virus shedding but have failed to provide sterilizing immunity. The efficacy of modified live-virus (MLV) vaccines is greater against a homologous strain compared with heterologous PRRSV strains. The objective of this study was to evaluate the efficacy of Fostera PRRS MLV vaccine in protecting against challenge with a heterologous field strain widely circulating in the swine herds of eastern Canada. Forty-six piglets were divided into 4 groups: nonvaccinated-nonchallenged; nonvaccinated-challenged; vaccinated-challenged; and vaccinated-nonchallenged. The animals were vaccinated at 23 d of age with Fostera PRRS and challenged 23 d later with a heterologous field strain of PRRSV (FMV12-1425619). Overall, the vaccine showed some beneficial effects in the challenged animals by reducing the severity of clinical signs and the viral load. A significant difference between nonvaccinated and vaccinated animals was detected for some parameters starting 11 to 13 d after challenge, which suggested that the cell-mediated immune response or other delayed responses could be more important than pre-existing PRRSV antibodies in vaccinated animals within the context of protection against heterologous strains.     

Establishment of an attenuated strain of bovine respiratory syncytial virus for live virus vaccine

To develop a live virus vaccine for the prevention of bovine respiratory syncytial (BRS) virus infection in calves, an attempt was made to produce an attenuated virus. The RS-52 strain of BRS virus, isolated from the nasal secretions of a naturally infected calf, was subjected to serial passages in adult hamster lung established (HAL) cells at 30 degrees C and the attenuated rs-52 strain as a live virus vaccine was established. The rs-52 strain multiplied better at 30 degrees C than at 34 or 37 degrees C in HAL cells. The differences in the highest virus titers of this strain between the culture temperature of 30 degrees C and that of 34 or 37 degrees C were more than 2.25 log TCID50. Colostrum-deprived newborn calves and 2 approximately 4 months old calves inoculated with the rs-52 strain manifested no abnormal clinical sings at all. However, all inoculated calves produced serum neutralization antibody. When the colostrum-deprived newborn calves immunized with the rs-52 strain were challenged with the virulent NMK7 strain of BRS virus, they exhibited no pyrexia or other abnormal clinical signs at all. An attempt was made to recover the virus from nasal secretions of these calves, but in vain. On the other hand, a nonimmunized control colostrum-deprived newborn calf developed slight fever, mild cough, and slight serous nasal discharge after challenge exposure. The virus was recovered from nasal secretions of this calf. From these results, it was considered that the rs-52 strain could be used as an attenuated live virus vaccine for prevention of BRS virus infection.     

猪伪狂犬病活疫苗(Bartha K61株)对变异株的保护效力

本研究旨在检测仔猪免疫猪伪狂犬病活疫苗(Bartha K61株)后,抵抗伪狂犬病病毒(PRV)变异株攻击的保护效果。取4~6周龄PRV抗体阴性仔猪,接种猪伪狂犬病活疫苗,1周后用PRV变异株(AH02LA株)攻毒,检测攻毒后临床症状、直肠温度、鼻腔排毒和肺部病变。疫苗免疫组在免疫后7 d均可以检测到gB抗体。攻毒对照组攻毒后出现典型伪狂犬症状,发病率为100%,死亡率为60%,所有猪只鼻拭子均检出排毒,所有猪只肺部均有出血、淤血等病变。免疫组的猪只攻毒后,所有猪只均未出现明显临床症状,部分猪只鼻拭子检出排毒,排毒持续时间缩短,排毒量显著减少,所有免疫猪只肺部未见明显病变。结果表明:伪狂犬病活疫苗免疫猪后对PRV变异株的攻击具有良好的保护效果。