不同新城疫疫苗对贵州三穗麻鸭的免疫效果比较

Comparison of the Immune Effect of Different Newcastle Disease Vaccines on Sansui Sheldrake Ducks in Guizhou Province

关键词:  新城疫病毒  三穗麻鸭  新城疫疫苗  免疫效果

Key words:  Newcastle disease virus  Sansui Sheldrake duck  Newcastle disease vaccine  immune effect

摘要:

为探讨不同新城疫（ND）疫苗对贵州三穗麻鸭的免疫效果，选用NDⅠ系活疫苗（CS2株）、Ⅳ系灭活疫苗（LaSota株）和重组基因Ⅶ型NDV灭活疫苗（A-Ⅶ株）分别对三穗麻鸭进行免疫实验，检测疫苗最小免疫剂量、免疫鸭的抗体滴度和消长规律，以及病毒感染免疫鸭后的排毒情况。结果显示，活疫苗CS2株、灭活疫苗LaSota株、灭活疫苗A-Ⅶ株的最小免疫剂量分别为1.0 mL/只、0.5 mL/只和0.2 mL/只；3种疫苗2次免疫要高于1次免疫产生的抗体滴度，但各免疫组不同免疫次数鸭的抗体滴度均在第60天达到高峰，其中以灭活疫苗A-Ⅶ株1次或2次免疫诱发的抗体滴度最高（分别为7.5log2和8.1log2），并且抗体持续期长，在免疫后第150天抗体水平仍能达到免疫保护要求；对免疫鸭的排毒检测发现，活疫苗CS2株免疫后的鸭持续排毒，灭活疫苗LaSota株免疫后的鸭排毒量少且时间短，而灭活疫苗A-Ⅶ株免疫后的鸭未检测到排毒。试验结果表明，重组基因Ⅶ型NDV灭活疫苗（A-Ⅶ株）在免疫剂量、免疫次数、免疫鸭的抗体滴度和持续时间，以及抑制免疫鸭排毒方面均明显优于传统ND疫苗。

Abstract:

To explore the immune effect of different Newcastle disease (ND) vaccines on Sansui Sheldrake ducks, ND live vaccine (CS2 strain), inactivated vaccine (LaSota strain) and recombinant genotype Ⅶ inactivated vaccine (A-Ⅶ strain) were used to inoculate 7-day-old ducks. The minimum immune dosage of vaccines, the dynamic regularity of antibody titers, and the virus shedding of immunized ducks were evaluated. Results showed that the minimum immune dosage of three vaccines was 1.0 mL, 0.5 mL and 0.2 mL, respectively. Although the antibody level induced by the vaccines with two immune times was higher than one immune time, the antibody titer of immunized ducks all reached a peak at 60 days post-immunization. However, both one and two immunization times of A-Ⅶ strain vaccine induced the highest antibody titer than other vaccines, which were 7.5log2 and 8.1log2, respectively. Meanwhile, the antibody persistent period of A-Ⅶ strain vaccine reached 150 days, which could still provide immunoprotection. Virus shedding experiment indicated that A-Ⅶ strain vaccine could absolutely suppress the virus shedding. These results demonstrated that recombinant genotype Ⅶ NDV inactivated vaccine (A-Ⅶ strain) is superior to the traditional ND vaccines in the aspects of the immune dosage, the immunization time, the titer and persistent period of antibody, and the inhibition of virus shedding.