OBJECTIVE: To evaluate the efficacy of a conditionally licensed commercial IBK vaccine containing Moraxella bovoculi bacterin. Primary working hypothesis was that animals vaccinated with 2 doses of the commercial M. bovoculi vaccine would have a lower risk of disease.
METHODS: Spring born calves at a university cow-calf herd. After excluding animals with ocular lesions, calves eligible for prevention assessment in 2017 and 2018 were 163 (81 vaccinated, 82 unvaccinated) and 207 (105 vaccinated, 102 unvaccinated). One hundred sixty two and two hundred and six calves completed the follow-up period in 2017 and 2018, respectively.
METHODS: A randomized controlled trial. The trial design was a 2-arm parallel trial with a 1:1 allocation ratio.
RESULTS: In both years, calves receiving the vaccine had more IBK. This effect was small. The pooled risk ratio was 1.30 (95% confidence interval 0.84-2.01). The pooled unadjusted difference in mean weight (kg) at weaning was -0.88 (95% confidence interval-7.2-5.43).
CONCLUSIONS: We were unable to document that the M. bovoculi bacterin vaccine had a protective effect for the incidence of IBK in our single herd in a 2-year study.
目的:评估一种有条件许可的商业IBK疫苗的效力,该疫苗含有博沃菌菌苗。主要的工作假设是,用2剂量的商业博沃武利分枝杆菌疫苗接种的动物将具有较低的疾病风险。
方法:在一所大学的牛牛群中春季出生的小牛。排除有眼部病变的动物后,2017年和2018年有资格参加预防评估的小牛为163只(81只接种了疫苗,82未接种疫苗)和207(105已接种疫苗,102未接种疫苗)。分别在2017年和2018年有106头和200头小牛完成了随访期。
方法:一项随机对照试验。试验设计为2臂平行试验,分配比例为1:1。
结果:在这两年中,接受疫苗接种的小牛有更多的IBK。这种影响很小。合并风险比为1.30(95%置信区间0.84-2.01)。断奶时平均体重(kg)的合并未调整差异为-0.88(95%置信区间-7.2-5.43)。
结论:在一项为期2年的研究中,我们无法证明,在我们的单群人群中,猪粪分枝杆菌菌苗对IBK的发病率有保护作用。