鸡新城疫抗体消长规律及血清抗体稳定性

Regularity of antibody fluctuation of Newcastle disease and serum antibody stability

为研究鸡新城疫灭活疫苗免疫后抗体消长规律及血清抗体稳定性,采用血凝抑制试验方法测定新城疫病毒-禽流感病毒(H9亚型)二联灭活疫苗免疫鸡血清新城疫抗体效价及经室温、4℃、-20℃、-80℃反复冻融和加热等不同方式处理的血清中新城疫抗体效价。结果表明,试验鸡于1日龄和21日龄用灭活疫苗免疫两次后,在第二次免疫后14 d新城疫抗体平均效价达到8.1 log_(2),35 d达到最高值为8.9 log_(2);免疫后70 d抗体效价保持在7.8 log_(2),且自二免后14~70 d,新城疫抗体效价维持在7.8 log_(2)~8.9 log_(2)。血清新城疫抗体在室温和4℃相对稳定,室温下放置13 d对新城疫抗体效价几乎无影响;但4℃保存9 d,对新城疫抗体效价有一定影响,且差异显著(P<0.05);56℃下30 min对新城疫抗体效价无影响;反复冻融3次对新城疫抗体效价影响极显著(P<0.01)。肉鸡于1日龄和21日龄用灭活疫苗免疫两次后,新城疫抗体水平高,且高水平抗体维持时间长。鸡血清新城疫抗体可耐56℃加热,室温保存活性稳定,反复冻融则影响其效价。

In order to study the rule of antibody fluctuation and stability of Newcastle disease antibody activity in serum after immunization with inactivated Newcastle disease vaccine,the hemagglutination inhibition test was used to determine the titers of Newcastle disease antibody in serum of chickens immunized with Newcastle disease virus and avian influenza virus(H9 subtype)dual inactivated vaccine.The titers of Newcastle disease antibody in serum treated by different methods such as room temperature,4 ℃ storage,-20 ℃,-80 ℃ freeze-thaw and heating were determined.The results showed that the average titer of Newcastle disease antibody reached 8.1 log_(2) at 14 d and 8.9 log_(2) at 35 d after the second immunization.The antibody titer remained 7.8 log_(2) at 70 d after immunization,and the antibody titer was 7.8 log_(2) to 8.9 log_(2) from 14 d to 70 d after the second immunization.The serum Newcastle disease antibody was relatively stable at room temperature and 4 ℃,and the titer of Newcastle disease antibody was almost not affected by room temperature for 13 days.However,the titer of Newcastle disease antibody was affected by 4 ℃ for 9 days,and the difference was significant(P<0.05).The titer of Newcastle disease antibody was not affected by 56 ℃ for 30 min.Repeated freeze-thaw for three times had a significant effect on the antibody titer of Newcastle disease(P<0.01).The results showed that the level of Newcastle disease antibody was high and the maintenance time of the high level of Newcastle disease antibody was long after the broilers were immunized with inactivated vaccine twice at 1 and 21 days of age.Newcastle disease antibody of chicken blood could resist heating at 56 ℃,and its activity was stable at room temperature.Repeated freezing and thawing could affect its titer.