鸡新城疫、传染性支气管炎、传染性法氏囊病三联弱毒疫苗的试制

用同胚培养的鸡新城疫Lasota株和传染性支气管炎H120（或H52）株以及用鸡胚成纤维细胞增殖的传染性法氏囊弱毒株以适当比例混合为抗原，用蔗糖脱脂乳作保护剂，经真空冷冻干燥制成三联弱毒疫苗。通过三批疫苗室内外各项指标的测试，表明该三联疫苗安全性能可靠，免疫效果确实，使用方法简便。在实验室进行的物理性状检验、无茵检验、支原体检验、剩余水分检验、真空度检查均符合国家标准；用10倍大剂量接种15日龄雏鸡无不良反应；以常规量颈部皮下接种免疫后，7d产生免疫力，免疫后14d抗鸡新城疫、鸡传染性支气管炎、鸡传染性法氏囊病三株强毒攻击的保护率均为，100％。对15日龄雏鸡首免，其免疫期至少为30d，在-25℃保存期为1年。

Study of Combined Attenuated Vaccine against Newcastl Disease Infectious Bronchitis Disease and Infectious Bursal Disease

Newcastle Disease（ND） Virus Lasota strain and Infections Bronchitis （IB） Virus H120 （or H52 ） strain were inoculated into chicken embryos and the allantoie fluid was collected. Infectious Bursal Disease （IBD） Virus BJ836 strain was inoculated into chicken embryo cells and the cultivate fluid was collected. Mixed the allantoic fluid and the cultivate fluid in appropriate proportion. The attempted triplex vaccine against ND, IB and IBD was prepared. The tests of 3 continuons batches of the triplex vaccine showed： It is reliable safety, exact immune effect ,simple and convenient administration. 15day old chickens showed no bad effect past inoculation with fifteen times normal dose. The chickens had immunity 7 days past inoculation at a normal dose by injection under skin in neck. The chickens obtained 100% protection rate against ND,IB and IBD, when they were challenged with the standard virulent. 15 days past inoculation. The immune protection period of the triplex was 30 days at least. The store period of the triplex vaccine was one year at - 25℃.