为了解羊只布鲁氏菌疫苗（S2株）口服免疫的安全性及免疫效果，在甘肃省平凉市2个乡镇，各选1个行政村，选择散养户饲养的264只羊作为试验羊，进行小范围的布鲁氏菌S2株活疫苗口服免疫试验，其中3月龄以上羊只（包括怀孕母羊）每只口服活菌100×2亿，3月龄以下羊每只口服活菌100亿。分别在免疫后的30、60、180、210 d，采集试验羊血清样品，采用虎红平板凝集（RBT）+试管凝集联合试验（SAT）、酶联免疫吸附试验（ELISA）进行血清抗体检测。结果显示：试验组羊只免疫后均未出现异常反应，口服免疫30 d后，试验羊只2种检测方法检测的免疫抗体阳性率分别为47.3%和53.8%，不同时间2种方法的检测结果基本一致（P＞0.05）。结果表明，布鲁氏菌S2株活疫苗按照试验剂量免疫安全有效，适用于所有月龄羊只以及怀孕母羊的整群免疫，可先行试点，逐步推广应用。
In order to identify the safety and immune effect of oral vaccination of Brucella live vaccine（S2），264 sheep raised by free-range households in one administrative village respectively in each of two towns of Pingliang City were vaccinated with the vaccine，in which，100×200 million live bacteria were orally administrated to each of the sheep over 3 months old（including pregnant ewes），but the dose was halved to those under 3 months old. The serum samples were collected at 30，60，180 and 210 days respectively after vaccination for detection of antibody by rose-bengal plate test（RBT）+standard tube agglutination test（SAT）and enzyme-linked immunosorbent assay（ELISA）. It was found that there was no any abnormal reaction in the immunized sheep，the antibody positive rates detected by the two methods were 47.3% and 53.8% respectively，with similar results at different times（P＞0.05）. It was concluded that the vaccine was safe and effective as per the dose specified in the experiment，which was appropriate for the immune of whole populations of pregnant ewes or the sheep at any months old，and could be applied in pilot and then gradually generalized to other areas.