Mawhinney I C, Burrows M R
ICM, Broadlands, Tut Hill, Bury St Edmunds IP28 6LE.
Vet Rec. 2005 Jan 29;156(5):139-43. doi: 10.1136/vr.156.5.139.
Twenty-one young calves with maternally derived antibody to bovine respiratory syncytial virus (BRSV) were divided into three groups of seven, each group balanced for BRSV antibody titre. The calves had no evidence of previous exposure to BRSV. The calves in one group were given a single dose of a monovalent modified live BRSV vaccine; the calves in the second group were given a single dose of an inactivated combined BRSV, parainfluenza virus type 3, Mannheimia haemolytica vaccine and the calves in the third group were left as unvaccinated controls. Three weeks after the single doses of vaccine, all the calves were challenged with BRSV. The clinical signs of disease were mild, and virus excretion was limited to two calves in the group given the inactivated vaccine, compared with six in the negative controls (P = 0.05) and five in the group given the live vaccine. The mean virus excretion titres after the challenge were not significantly different between the groups. There was little seroconversion before the challenge, but six of the seven calves in the group given the inactivated vaccine showed significant seroconversion within two weeks after the challenge, compared with only one calf in each of the other two groups (P = 0.015).
21头携带源自母体的牛呼吸道合胞病毒（BRSV）抗体的幼犊被分成三组，每组7头，每组的BRSV抗体滴度均衡。这些幼犊没有先前接触过BRSV的迹象。一组幼犊接种单剂量单价BRSV改良活疫苗；第二组幼犊接种单剂量BRSV、3型副流感病毒、溶血曼氏杆菌灭活联合疫苗，第三组幼犊作为未接种疫苗的对照。单剂量疫苗接种三周后，所有幼犊均用BRSV进行攻毒。疾病的临床症状较轻，与阴性对照组的6头和接种活疫苗组的5头相比，接种灭活疫苗组仅有2头幼犊出现病毒排泄（P = 0.05）。攻毒后各组的平均病毒排泄滴度无显著差异。攻毒前几乎没有血清转化，但接种灭活疫苗组的7头幼犊中有六头在攻毒后两周内出现显著血清转化，而其他两组每组只有一头幼犊出现血清转化（P = 0.015）。
