免疫增强剂提高禽用多联疫苗在蛋鸡的免疫效力

The Effect of Immunopotentiators on Improving the Efficacy of Multivalent Vaccine in Laying Hens

评价VA5免疫增强剂对禽用多联苗的免疫增强作用。将VA5与新城疫-传染性支气管炎-减蛋下降综合症-H9亚型禽流感(新-支-减-流)四联疫苗合用免疫海兰褐壳蛋鸡和罗曼蛋鸡、与新-支-流三联疫苗合用免疫海兰褐壳蛋鸡,评价免疫后的抗体效价和攻毒后的保护效力。海兰褐壳蛋鸡或罗曼蛋鸡免疫含VA5的四联疫苗、三联疫苗后的第2、第3和第4周,针对新城疫、传支、减蛋综合征和禽流感的血清血凝抑制(HI)抗体效价均持续高于不加增强剂的常规疫苗组,且第3和第4周HI抗体效价均差异显著(P<0.05);针对新城疫、传支、减蛋综合征和禽流感的粘膜HI抗体效价均亦高于不加增强剂的常规苗组,且差异极显著(P<0.01)。免疫含VA5四联疫苗组的海兰褐壳蛋鸡,在新城疫强毒攻毒后,以临床症状判断,可以100%保护;在禽流感H9变异株攻毒后,可完全抑制不排毒。对上述2种病毒的攻毒保护力均高于常规疫苗。结果表明,VA5免疫增强剂能够提高鸡新-支-减-流四联疫苗、新-支-流三联疫苗对蛋鸡的免疫效力,具有很好的应用前景。

The aims of this study is to evaluate the effect of VA5 immunopotentiator on improving the efficacy of multivalent vaccine in laying hens.The antibody titer and protective efficacy were evaluated after the VA5 was mixed with the commercial tetravalent vaccine,Newcastle disease(ND)-Infectious Bronchitis(IB)-Egg Drop Syndrome(EDS)-H9 Subtype Avian Influenza(H9 AI)vaccinated in Hy-line brown and Lohmann laying hen breeds,or with trivalent vaccine,ND-IB-AI(H9)vaccinated in Hy-line brown breeds.In the vaccination groups of tetravalent vaccine with VA5 or trivalent vaccine with VA5,the hemagglutinin inhibition antibody titers of sera against ND,IB,EDS and H9 AI were higher than those of the groups vaccinated with tetravalent vaccine without VA5 or trivalent vaccine without VA5 at 2-,3-,and 4-week post vaccination(pv),and those differences were significant(P<0.05),respectively.Similar to the HI antibody levels,the mucosal antibody levels against ND,IB,EDS and H9 AI were higher in the groups of tetravalent vaccine with VA5 than those of the tetravalent vaccine only and those differences were significant(P<0.01).The protective efficacy of tetravalent vaccine was also improved by VA5 immunopotentiators.During the ND virus challenge test,birds did mot show any clinical symptoms in the group of tetravalent vaccine with VA5 which were superior than those birds in the tetravalent vaccine only group.In the H9 AI virus challenge test,no bird shedding virus in the group of tetravalent vaccine plus VA5,however,birds shedding virus were observed in the group of tetravalent vaccine without VA5.Taken together,the VA5 has effect on improving the efficacy of tri-or tetra-valent vaccine in laying hens and shows prosperity in application.