کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5799543 | 1111842 | 2007 | 9 صفحه PDF | دانلود رایگان |
Two experimental bovine respiratory syncytial virus (BRSV) challenge studies were undertaken to evaluate the efficacy of a single intranasal dose of a bivalent modified live vaccine containing BRSV in 3-week-old calves. In the first study, vaccine efficacy was evaluated in colostrum deprived (maternal antibody negative) calves 5, 10 and 21Â days after vaccination. Nasal shedding of BRSV was significantly reduced in vaccinated calves challenged 10 or 21Â days after vaccination. Virus excretion titres were also reduced in vaccinates challenged 5Â days after vaccination but reduction in duration of shedding and total amount of virus shed were not statistically significant. Clinical disease after challenge in this study was mild. In the second study, vaccine efficacy was assessed in calves with maternal antibodies against BRSV by challenge 66Â days post-vaccination. Vaccination significantly reduced nasal shedding after challenge and the severity of clinical disease was also reduced.
Journal: The Veterinary Journal - Volume 174, Issue 3, November 2007, Pages 627-635