禽霍乱-新城疫二联油乳剂灭活疫苗研究Ⅱ报——疫苗的免疫持续期及保存期试验

Study on Inactivated Vaccine in Oil Emulsion Against Newcastle Disease and Fowl Cholera Ⅱ——Immunity Persistence and Preservation of Vaccine

采用新城疫病毒(NDV)Lasota株感染鸡胚尿囊液毒和多杀性巴氏杆菌(禽A型)接种固体培养基收获菌液,经灭活后制备成5批油乳剂灭活苗(批号2001-1～2001-5),用于免疫2月龄以上的青年鸡,试验分一次免疫组和二次免疫组,分别在免疫后1个月、3个月、6个月、9个月进行ND和FC强毒攻击保护试验,结果表明,相同剂量分两次免疫,近期效果差异不明显。一次免疫组,6个月攻毒ND的保护为100/、FC保护为80/;8个月攻毒ND的保护为95/、FC保护为52.5/。二次免疫组,6个月攻毒ND的保护为100/,HI抗体1∶64以上;FC攻毒保护87.5/;8个月攻毒ND的保护为100/,FC保护为77.5/。疫苗保存期试验证明,4～8℃冰箱保存可达18个月,10～20℃保存的有效期为4个月。

Allantoic fluid from embryonic eggs infected with Newcastle disease virus （strain Lasota） and bacteria from solid culture medium inoculated with poultry Pasteurella multocida were collected and inactivated for 5 subsequent lots （lots No. 2001-1, 2001-2, 2001-3, 2001-4, 2001-5） of vaccine preparation in oil emulsion. The prepared vaccine was vaccinated into chickens older than 2 months. The chickens were divided into two groups. The vaccinated chickens were challenged with virulent NDV and poultry Pasteurella multocida for protection test in 1, 3, 6, 9mohths post-inoculation （p.i.） respectively. The results showed that it had no significant efficiency difference in short period of time when the same dose of vaccine was delivered to chickens once or twice. In the group of inoculation once the protection rate was 100% for NDV and 80% for Fowl Cholera （FC） 6 months p.i., and 95% for NDV and 52.5% for FC 9 months p.i.. And in the group of inoculation twice, HI ≥ 1：64 and the rates of protection were 100% for ND and 87.5% for Fowl Cholera 6 months p.i., 100% for ND and 77.5% for FC 8 months p.i.. Preservation test showed that the prepared vaccine could be preserved for 18 months at 4-8℃ and 4 months at 10-20℃ .