两种新城疫灭活疫苗免疫原性比较

Comparison of Immunogenicity of Two Inactivated Newcastle Disease Vaccines

新城疫作为家禽养殖业危害最大的疫病之一,近些年来常发生免疫失败的现象,究其原因,由于免疫压力的增大和变异株的增多,使疫苗的免疫效果受到极大的挑战,因此选择合适的病毒株制备疫苗对免疫效果具有重要的意义。论文通过测定抗体水平比较新城疫基因Ⅶ型A-Ⅶ株和传统基因Ⅱ型La Sota株油乳剂灭活疫苗对鸡只免疫效价的影响,通过攻毒后的保护、排毒情况及病毒载量的研究,综合比较了2种毒株的免疫原性。通过本试验发现,利用基因Ⅶ型A-Ⅶ株灭活苗与基因Ⅱ型La Sota株灭活苗免疫SPF鸡后,A-Ⅶ株灭活苗所产生的HI抗体效价明显高于La Sota株灭活苗。而通过基因Ⅶ型YND株和标准强毒F48E9株攻毒试验结果显示,2种疫苗均能100%的保护鸡只不死亡,但A-Ⅶ株比La Sota株灭活苗能够更好地抑制强毒在体内的复制和排毒。由此可见,基因Ⅶ型A-Ⅶ株对不同基因型强毒的抵抗能力优于基因Ⅱ型La Sota株,具有更好的免疫原性,通过本试验可为新城疫的防控选择合适的疫苗提供一定的参考。

Newcastle disease is one of the most severe diseases in poultry industry.In recent years,immune failure has frequently occurred.The reason is that the immune response of the vaccines is greatly challenged by the increase of immune pressure and the increase of mutant strains.Therefore,it is important for the im- mune effect to choose the appropriate strain for vaccine preparation.In this article,by measuring antibody levels,we compared the immunogenicities and effects of Newcastle disease genotype A-Ⅶ strain and tra- ditional genotype II La Sota oil emulsion inactivated vaccines on antibody titers of chickens,the protection andshedding,and viral loads after virus challenge. The results showed that the titer of HI antibody pro- duced by immunized SPF chickens with inactivated vaccine contained genotype A-Ⅶ strain was signifi- cantly higher than that with inactivated vaccine contained genotype II La Sota strain.The results showed that both vaccines yielded 100% protection to mortality,but the A-Ⅶ strain can protect the virus from rep- lication and shedding significantly than La Sota strain,detecting by challenging with F48 E9 strain and geno- type Ⅶ YND strain. The result suggested that individually immunized with genotype A-Ⅶ strain at- tained superior protection than that immunized with genotype II La Sota strain,which has inferior immu- nogenicity.The result of the study provided a suggestion in selection of appropriate Newcastle disease vac- cine in disease control.