传染性法氏囊病病毒变异株弱毒的免疫原性研究

Immunogenicity of Attenuated Variant Strains of Infectious Bursal Disease Virus

传染性法氏囊病病毒 (IBDV)JD1、JD2 、NB变异株和HZ1、SC经典株弱毒分别以 30 0 0TCID50 、5 0 0 0TCID50 、10 0 0 0TCID50 、5 0 0 0TCID50 剂量免疫SPF鸡后的攻毒试验结果表明 :IBDV_NB、JD1、HZ1弱毒株可诱导SPF鸡产生很高的血清中和抗体 ,具有优良的免疫原性 ,强毒攻击保护率均达 10 0 %。IBDV_NB毒株的最佳免疫剂量为 30 0 0TCID50 ,IBDV_JD1和HZ1毒株的最佳免疫剂量为 5 0 0 0TCID50 。抗体消长规律表明NB毒株一次免疫的有效保护期可达 2 74天 ,JD1和HZ1毒株为 2

day_old SPF chickens were vaccinated with three attenuated variant strains(JD 1、JD 2、NB) and two classic strains(HZ 1、SC)of infectious bursal disease virus(IBDV)at four different doses (3000TCID 50 |5000TCID 50 |10000TCID 50 |15000TCID 50 )for exploring the immunogenicity of these attenuated IBDVs.The results show that the attenuated IBDV_JD 1,NB and HZ 1 can induce SPF chickens to produce better immune responses,and the protection ratio of the vaccinated chickens was 100% after challenging with the virulent IBDV_BC6/85.The optimal vaccination dose was 5000TCID 50 for IBDV strains JD 1 and HZ 1,while 3000TCID 50 for IBDV strain NB.The effective protection time of the vaccine was 274 days with IBDV strain NB,214 days for both JD 1 and HZ 1 strains of IBDV after primary immunization.