布鲁氏菌弱毒活疫苗对绵羊全群免疫的探讨

Study on the Whole Population Immunity of Sheep with Live Attenuated Brucella Vaccine

本试验将布鲁氏菌病疫苗S2株、M5株和布鲁氏菌基因缺失弱毒活疫苗(BA0711株)中试制品,以标定剂量分别接种怀孕中后期绵羊、1月龄内羔羊和1~2月龄羔羊,测定3种疫苗或制品对怀孕绵羊和羔羊的安全性和免疫反应性。结果显示,与对照组相比,S2株疫苗口服组试验羊体温、食欲和精神状况基本正常;皮下接种S2株疫苗、M5株疫苗和BA0711株制品的所有绵羊,都存在2~3 d体温反应,但精神、食欲基本正常,其中S2株和M5株皮下接种的2组孕羊各有10%个体流产。3个年龄段试验羊抗体反应性测定结果显示,成年孕羊抗体反应性最强,1月龄内羔羊最差;口服接种S2株疫苗诱导的抗体水平显著低于S2株疫苗的皮下注射组,而3种疫苗皮下注射接种绵羊在抗体反应和维持时间上无显著差异。本试验表明,S2株疫苗口服接种或BA0711株制品皮下接种对孕羊的安全性良好。鉴于1月龄内羔羊对疫苗接种的免疫反应性弱,而1~2月龄羔羊接近成年羊,建议在大规模免疫防控时,羊群内2月龄以上所有羊只全部接种,以阻断布鲁氏菌病在群内传播和蔓延。

In this study,we inoculated sheep in the middle and late trimester of pregnancy,lambs within 1 month of age,and lambs aged 1-2 months with standard doses of brucellosis vaccine S2,M5 and BA0711 strains,and analyzed the safety and immunogenicity of the 3 vaccines to pregnant sheep and lambs.The results showed that compared with the control group,the body temperature,appetite and mental state of the sheep in the S2 vaccine oral vaccination group were basically normal.In the sheep of S2 vaccine,M5 vaccine and BA0711 strain subcutaneous vaccination group,the body temperature reaction were 2-3 days.But the spirit and appetite of the sheep were all normal,and 10%of the pregnant sheep had abortion in the S2 and M5 vaccine subcutaneous vaccination group,respectively.The antibody reactivity in the adult pregnant sheep was the strongest in the three age groups,and in the lambs of one month of age was the worst.The antibody level induced by oral vaccination of S2 strain was significantly lower than that in S2 strain subcutaneous vaccination group.There was no significant difference in antibody response and antibody duration among the three vaccines.This study showed that oral vaccination of S2 strain or subcutaneous vaccination of BA0711 strain was safe for pregnant sheep.In view of the weak immune response in lambs to vaccination within 1 month of age,while the lambs aged 1-2 months were close to adult sheep,it was suggested that all sheep over 2 months of age should be vaccinated in large scale immunization to prevent the spread of Brucellosis in the herd.