Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706.
Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada.
J Dairy Sci. 2018 Sep;101(9):8159-8168. doi: 10.3168/jds.2017-14271. Epub 2018 Jun 13.
The objective of this field trial was to evaluate the effect of a vaccine protocol using a commercially available trivalent vaccine designed for intranasal use. Experimental challenge studies have demonstrated varying efficacies of vaccines administered via the intranasal route. A total of 468 calves from 3 herds were enrolled and randomized into 3 treatment groups (positive control, PC, n = 211; intranasal vaccine, IN, n = 215; negative control, NC, n = 42) and followed for 8 to 12 wk. The PC consisted of one dose of commercially available multivalent injectable vaccine against bovine respiratory syncytial virus, infectious bovine rhinotracheitis, parainfluenza 3, and bovine viral diarrhea administered subcutaneously at 6 wk of age. The IN was administered at enrollment and 6 wk of age, and contained antigen against bovine respiratory syncytial virus, infectious bovine rhinotracheitis, and parainfluenza 3. The NC was sterile saline administered intranasally and subcutaneously at enrollment and 6 wk of age. Clinical illness was assessed using systematic respiratory scoring, and thoracic ultrasonography was used to identify the lung consolidation associated with pneumonia. Rib fractures were identified in 6% of calves, and an association was observed between rib fractures and calving ease. Overall, 54% of the calves had at least one episode of an abnormal respiratory score (ILL). Vaccination protocol did not affect the occurrence of ILL. Similarly, 54% of the calves had at least one episode of lung consolidation ≥3 cm (CON). Vaccine protocol affected the odds of CON. The odds of CON in PC were 1.63 (95% confidence interval: 1.04-2.56) times the odds of CON in IN, and 0.38 (95% confidence interval: 0.16-0.93) times the odds of CON in NC. The odds of CON in IN were 0.23 (95% confidence interval: 0.09-0.59) times the odds of CON in NC. The outcomes ILL and CON were associated; however, the measure of agreement was only fair (kappa = 0.38). Multivariable linear regression revealed an interaction between vaccine protocol and herd on average daily gain (ADG); therefore, these data were stratified. In herd 1, IN (0.53 ± 0.03 kg/d) decreased ADG compared with PC (0.63 ± 0.03 kg/d). In herd 2, IN increased ADG (0.41 ± 0.03 kg/d) compared with PC (0.38 ± 0.03 kg/d). In contrast, none of the protocols affected ADG at herd 3. In conclusion, this commercially available trivalent IN vaccine protocol did not alter the incidence of ILL, reduced the risk of lung lesions associated with pneumonia, and improved the ADG of the calves in one of the commercial study herds.
本田间试验的目的是评估使用市售三价鼻内用疫苗进行疫苗接种方案的效果。实验性挑战研究表明，通过鼻内途径给予的疫苗具有不同的功效。共有来自 3 个牛群的 468 头小牛被纳入并随机分为 3 个治疗组（阳性对照，PC，n = 211；鼻内疫苗，IN，n = 215；阴性对照，NC，n = 42），并随访 8 至 12 周。PC 包括在 6 周龄时皮下接种市售多价注射用牛呼吸道合胞体病毒、传染性牛鼻气管炎、副流感 3 和牛病毒性腹泻疫苗。IN 在入组时和 6 周龄时接种，含有针对牛呼吸道合胞体病毒、传染性牛鼻气管炎和副流感 3 的抗原。NC 在入组时和 6 周龄时鼻内和皮下给予无菌生理盐水。使用系统呼吸评分评估临床疾病，使用胸部超声识别与肺炎相关的肺实变。6%的小牛有肋骨骨折，观察到肋骨骨折与产犊难易度有关。总体而言，54%的小牛至少有一次异常呼吸评分（ILL）发作。疫苗接种方案并未影响 ILL 的发生。同样，54%的小牛至少有一次肺实变≥3cm（CON）发作。疫苗接种方案影响 CON 的可能性。PC 中 CON 的可能性是 IN 中 CON 可能性的 1.63 倍（95%置信区间：1.04-2.56），是 NC 中 CON 可能性的 0.38 倍（95%置信区间：0.16-0.93）。IN 中 CON 的可能性是 NC 中 CON 可能性的 0.23 倍（95%置信区间：0.09-0.59）。ILL 和 CON 的结果相关；然而，一致性的衡量标准仅为中等（kappa = 0.38）。多变量线性回归显示疫苗接种方案和牛群之间存在平均日增重（ADG）的相互作用；因此，对这些数据进行了分层。在牛群 1 中，IN（0.53 ± 0.03 kg/d）降低了 ADG，而 PC（0.63 ± 0.03 kg/d）则增加了 ADG。在牛群 2 中，IN 增加了 ADG（0.41 ± 0.03 kg/d），而 PC 降低了 ADG（0.38 ± 0.03 kg/d）。相比之下，在牛群 3 中，没有任何方案会影响 ADG。总之，这种市售的三价鼻内用疫苗接种方案并未改变 ILL 的发生率，降低了与肺炎相关的肺损伤的风险，并提高了一个商业研究牛群中小牛的 ADG。
