Ficken Martin D, Ellsworth Michael A, Tucker Cassius M, Cortese Victor S
Pfizer Animal Health, 601 W Cornhusker Hwy, Lincoln, NE 68521, USA.
J Am Vet Med Assoc. 2006 May 15;228(10):1559-64. doi: 10.2460/javma.228.10.1559.
To compare the efficacy of modified-live virus (MLV) vaccines containing either type 1 bovine viral diarrhea virus (BVDV) or types 1 and 2 BVDV in protecting heifers and their offspring against infection associated with heterologous noncytopathic type 2 BVDV challenge during gestation.
Randomized controlled study.
160 heifers and their offspring.
After inoculation with a placebo vaccine, 1 or 2 doses of an MLV vaccine containing type 1 BVDV, or 1 dose of an MLV vaccine containing both types 1 and 2 BVDV, heifers were bred naturally and challenge exposed with a type 2 BVDV field isolate between 62 and 104 days of gestation. Pregnancies were monitored; after parturition, virus isolation and immunohistochemical analyses of ear-notch specimens were used to determine whether calves were persistently infected. Blood samples were collected at intervals from heifers for serologic evaluation and virus isolation.
Persistent infection was detected in 18 of 19 calves from heifers in the control group and in 6 of 18 calves and 7 of 19 calves from heifers that received 1 or 2 doses of the type 1 BVDV vaccine, respectively. None of the 18 calves from heifers that received the type 1-type 2 BVDV vaccine were persistently infected.
Results suggest that the incidence of persistent BVDV infection among offspring from dams inoculated with 1 dose of the MLV vaccine containing types 1 and 2 BVDV was decreased, compared with 1 or 2 doses of the MLV vaccine containing only type 1 BVDV.
比较含1型牛病毒性腹泻病毒（BVDV）的减毒活疫苗（MLV）与含1型和2型BVDV的MLV疫苗在保护小母牛及其后代免受妊娠期间异源非细胞病变型2型BVDV攻击相关感染方面的效果。
随机对照研究。
160头小母牛及其后代。
用安慰剂疫苗接种后，给小母牛接种1剂含1型BVDV的MLV疫苗、2剂含1型BVDV的MLV疫苗或1剂含1型和2型BVDV的MLV疫苗，然后使其自然受孕，并在妊娠62至104天之间用1株2型BVDV野外分离株进行攻击暴露。监测妊娠情况；分娩后，通过病毒分离和耳部切口标本的免疫组织化学分析来确定犊牛是否受到持续性感染。从小母牛身上定期采集血样进行血清学评估和病毒分离。
对照组小母牛所产的19头犊牛中有18头被检测出持续性感染，接受1剂或2剂1型BVDV疫苗的小母牛所产的犊牛中，分别有18头中的6头和19头中的7头被检测出持续性感染。接受1型-2型BVDV疫苗的小母牛所产的18头犊牛中无一例被检测出持续性感染。
结果表明，与接种1剂或2剂仅含1型BVDV的MLV疫苗相比，接种1剂含1型和2型BVDV的MLV疫苗的母畜所产后代中BVDV持续性感染的发生率有所降低。
