Nettleton P F, Brebner J, Pow I, Gilray J A, Bell G D, Reid H W
Moredun Research Institute, Edinburgh.
Vet Rec. 1996 Feb 24;138(8):184-6. doi: 10.1136/vr.138.8.184.
Twenty, eight-day-old specific pathogen-free (SPF) lambs were vaccinated by a single scarification approximately 4 cm in length on the inner right thigh with a double-pronged applicator. The titre of live virus in the vaccine was 10(7.2) TCID50/ml and the estimated dose per lamb was 0.04 ml. Three months and six months later 10 of the vaccinated lambs and five age-matched unvaccinated control specific pathogen free lambs were challenged by a single scarification with virulent virus on the inner left thigh in the same way. After the vaccination all 20 lambs developed lesions characteristic of orf virus infection that had largely resolved four weeks later, when they all had reciprocal ELISA antibody titres > or = 3200 that persisted in all but one of them until they were challenged. After the challenge, the development of lesions in the vaccinated and unvaccinated sheep was compared daily for four weeks by means of a clinical scoring system. Both groups of vaccinated lambs had significantly lower (P < 0.01) total clinical scores after challenge at three months and six months than the unvaccinated lambs.
20只28日龄的无特定病原体（SPF）羔羊，通过使用双叉涂抹器在右大腿内侧进行单次划痕接种疫苗，划痕长度约4厘米。疫苗中活病毒滴度为10(7.2) TCID50/ml，每只羔羊估计剂量为0.04毫升。三个月和六个月后，10只接种疫苗的羔羊和5只年龄匹配的未接种疫苗的对照无特定病原体羔羊，以同样的方式在左大腿内侧进行单次划痕接种强毒病毒攻毒。接种疫苗后，所有20只羔羊均出现了口疮病毒感染的特征性病变，四周后这些病变基本消退，此时它们的ELISA抗体效价均≥3200，除一只羔羊外，其余羔羊的抗体效价一直持续到攻毒时。攻毒后，通过临床评分系统，对接种疫苗和未接种疫苗的绵羊在四周内每天的病变发展情况进行比较。在三个月和六个月攻毒后，两组接种疫苗的羔羊的总临床评分均显著低于（P < 0.01）未接种疫苗的羔羊。
