新城疫病毒弱毒疫苗的免疫研究

新城疫病毒长春株（ＮＤＶ ＣＣ株）经生物学及分子生物学特性研究证明为新城疫病毒弱毒株,以ＮＤＶ ＣＣ毒株制成弱毒疫苗,采用饮水、滴鼻和肌肉注射免疫等方式,分别免疫７日龄雏鸡,免疫鸡未出现不良反应。免疫后７ｄＨＩ效价为２＾５以上,６０ｄ后均能维持较高的ＨＩ值,免疫后１４ｄ用ＮＤＶ强毒攻击,其保护率可达到１００％（１０／１０）。     

鸡沙门氏菌弱毒苗的安全性和免疫效力试验

把鸡沙门氏菌弱毒苗按不同剂量分别经口服和颈部皮下接种１日龄商品蛋鸡来进行安全性和免疫效力研究,结果表明：该疫苗对１日龄雏鸡有良好的安全性并能提供较强的保护力。     

鸡新城疫HI抗体对弱毒疫苗免疫的影响

按雏鸡的ＨＩ抗体水平分为低抗体组、中等抗体组和高抗体组３个组，每组又分为４个小组，分别用于Ｆ系疫苗饮水、Ｉ系疫苗肌注和Ｉ系疫苗饮水试验，另一小组不免疫作为对照，免疫后１０天，２０天分别采血清进行ＨＩ价测定，结果表明，不ＨＩ抗体水平雏鸡产生的免疫效果各异，免疫前基础抗体水平对弱毒疫苗的免疫效应具有明显影响。     

ND弱毒疫苗局部免疫与全身免疫效果的比较

对非免疫小鸡随机分组后．分别于25日龄和32日龄采用ND Ⅳ系疫苗(滴鼻、点眼)进行局部免疫．I系疫苗全身免疫肌肉注射．NDIV系疫苗局部免疫(滴鼻、点眼)联合I系疫苗全身免疫肌肉注射3种不同免疫方法处理后，于39日龄以NDLD野毒株分别以滴鼻、点眼和(或)肌肉注射进行攻毒．比较各组的免疫保护率。结果表明：全身免疫与局部免疫联合免疫组效果显著好于单纯的局部免疫或全身免疫的效果．且在49日龄ND HI抗体水平可达1：1280。     

法氏囊活性肽对新城疫弱毒疫苗免疫效果影响的研究

本研究通过鸡两次注射法氏囊活性肽后,接种新城疫弱毒疫苗,观察法氏囊活性肽对新城疫弱毒疫功免疫效果的影响,结果表明,纯化的法氏囊活性肽能够提高新城疫弱毒疫苗所诱导产生的血清抗体水平,试验组比对照线平均高１～２个滴度,使血清母源新城疫抗体水平维持较高水平,促进法氏囊的生长发育,对抗传染性法氏囊弱疫苗（ＩＢＤ）对法氏囊的损伤,和（或）促进损伤后的法氏囊的修复,对脾脏的生长发育同有影响。     

新城疫三种弱毒疫苗对肉用鸡比较免疫试验

新城疫三种弱毒疫苗对肉用鸡比较免疫试验辽宁省普兰店市兽医卫生站，１１６２００南京农业大学动物医学院多年来，普兰店市肉用鸡新城疫的免疫程序是７～１４日龄用Ｆ系或ＬａＳｏｔａ株（Ⅳ系）弱毒疫苗首次免疫，一个月再次免疫。由于这两种弱毒苗推广应用时间较长和母...     

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%     

中药复方散剂对肉鸡生长及鸡新城疫灭活油苗免疫效果的影响

将玉屏风散、十全大补汤、六味地黄丸三个中药复方散剂分别按1%剂量添加到科宝快大型白鸡日粮中, 于雏鸡14日龄, 按0.5 ml/只剂量肩部肌肉注射鸡新城疫灭活油乳剂疫苗, 即日起饲喂上述饲料, 并按40 mg/kg剂量胸肌注射环磷酰胺,每天1次, 连续3天; 免疫后第10天、 20天、 30天采血检测鸡新城疫HI抗体效价,观测鸡增重情况,免疫后第15天、 25天检测血清总蛋白含量.实验结果表明,玉屏风散、六味地黄丸能显著提高鸡新城疫HI抗体效价(P<0.05),十全大补汤的作用不明显;玉屏风散、十全大补汤能显著增加肉鸡体重(P<0.05),六味地黄丸的作用不明显,实验组鸡死亡率均降低;玉屏风散、十全大补汤能显著提高血清总蛋白含量(P<0.05),六味地黄丸的作用不明显.     

Immunisation of fancy chickens against Newcastle disease]

The German Regulation on Fowl plague which is in force since 1994 laid down that any chicken of all races and all hybrids must be vaccinated against Newcastle disease (ND) in a mode that an adequate immunity is achieved. Onset, duration, and resistance to challenge of immunity induced by vaccination is well documented in the scientific literature for hybrid chicken of the layer and meat types. These data prove also innocuity and efficacy of the registered vaccines. In contrast, only a few and incomplete data exist on the development of ND directed immunity in fancy chickens. The present study describes vaccinations of chickens of 14 different hobby breeds with live LaSota vaccine (conjunctival application of 10(6) embryo-infective dose50 per bird) and with an inactivated oil-emulsion vaccine (intramuscular application of 0.5 ml per bird) and subsequent intramuscular challenge infections using the highly virulent NDV strain Herts 33/66. Chickens of all 14 breeds tolerated the application of both vaccines. All fancy chickens reacted with the production of serum antibodies which were measured in the haemagglutination inhibition (HI) and virus neutralisation (VN) tests. According to the scientific literature, maximal antibody levels are reached in hybrid chickens between day 10 and 20 post vaccination. In contrast, in fancy chickens the antibody maxima are delayed to the seventh to eighth week post vaccination. All fancy chickens vaccinated either once with live LaSota virus or with live and inactivated vaccines resisted challenge with the highly virulent Herts 33/66 strain of NDV and did not develop any signs of disease. There are indications for gradual differences in susceptibility of different breeds of fancy chickens. The levels of non-specific neutralisation as measured in the virus neutralisation test differ between breed. Also, the viral content in tissues obtained from non-vaccinated but challenged birds differ markedly. It is concluded from the results of this study that fancy chickens can also successfully protected against Newcastle disease by using live and inactivated vaccines which are licensed for hybrid chickens. However, the optimal time for the detection of maximal antibody levels in fancy chickens is reached seven to eight weeks post vaccination.     

Immunization of day-old chickens against Newcastle disease.

The avirulent Newcastle disease virus strain designated NDV-6/10, selected by B. Lomniczi at the Veterinary Medical Research Institute, Hungarian Academy of Sciences, is completely safe for day-old chickens by aerosol vaccination. Aerosol immunization using the Hungarian-made MASTERDROP generator (particle size: maximum 7 microns) caused no vaccination reactions among 206,000 chickens with different maternal antibody levels. Other vaccines given simultaneously did not significantly affect the protection elicited against Newcastle disease (ND). Almost 100% and 90% of the aerosolized chickens survived subcutaneous challenge with 10(6) LD50 NDV at 30 and 50 days old, respectively. A single immunization is sufficient for broilers; however, parent flocks should be revaccinated at 7 so 8 weeks old.     

Protective efficacy of commercial inactivated Newcastle disease virus vaccines in chickens against a recent Korean epizootic strain

Despite the intensive vaccination policy that has been put in place to control Newcastle disease virus (NDV), the recent emergence of NDV genotype VII strains in Korea has led to significant economic losses in the poultry industry. We assessed the ability of inactivated, oil-emulsion vaccines derived from La Sota or Ulster 2C NDV strains to protect chickens from challenge with Kr-005/00, which is a recently isolated Korean epizootic genotype VII strain. Six-week-old SPF chickens were vaccinated once and challenged three weeks later via the eye drop/intranasal route. All vaccinated birds were fully protected from disease, regardless of the vaccine strains used. All vaccinated and challenged groups showed significant sero-conversion 14 days after challenge. However, some vaccinated birds, despite being protected from disease, shed the challenge virus from their oro-pharynx and cloaca, albeit at significantly lower titers than the unvaccinated challenged control birds. The virological, serological, and epidemiological significance of our observations with regard to NDV disease eradication is discussed.