Intervet/Schering-Plough Animal Health, 35500 W. 91st Street, De Soto, KS 66018, USA.
Vaccine. 2010 Dec 10;29(1):70-6. doi: 10.1016/j.vaccine.2010.10.012. Epub 2010 Oct 27.
Vaccination plays a significant role in the control of bovine viral diarrhea virus (BVDV) infection and spread. Recent studies revealed that type 1b is the predominant BVDV type 1 subgenotype, representing more than 75% of field isolates of BVDV-1. However, nearly all current, commercially available BVDV type 1 vaccines contain BVDV-1a strains. Previous studies have indicated that anti-BVDV sera, induced by BVDV-1a viruses, show less neutralization activity to BVDV-1b isolates than type 1a. Therefore, it is critically important to evaluate BVDV-1a vaccines in their ability to prevent BVDV-1b infection in calves. In current studies, calves were vaccinated subcutaneously, intradermally or intranasally with a single dose of a multivalent, modified-live viral vaccine containing a BVDV-1a strain, and were challenged with differing BVDV-1b strains to determine the efficacy and duration of immunity of the vaccine against these heterologous virus strains. Vaccinated calves, in all administration routes, were protected from respiratory disease caused by the BVDV-1b viruses, as indicated by significantly fewer clinical signs, lower rectal temperatures, reduced viral shedding and greater white blood cell counts than non-vaccinated control animals. The BVDV-1a vaccine elicited efficacious protection in calves against each BVDV-1b challenge strain, with a duration of immunity of at least 6 months.
疫苗接种在控制牛病毒性腹泻病毒（BVDV）感染和传播方面发挥着重要作用。最近的研究表明，1b 型是主要的 BVDV-1 亚基因组 1 型，占 BVDV-1 的超过 75%。然而，目前几乎所有市售的 BVDV-1 型疫苗都含有 BVDV-1a 株。先前的研究表明，由 BVDV-1a 病毒诱导的抗 BVDV 血清对 BVDV-1b 分离株的中和活性低于 1a 型。因此，评估 BVDV-1a 疫苗预防犊牛 BVDV-1b 感染的能力至关重要。在目前的研究中，小牛通过皮下、皮内或鼻内接种一剂包含 BVDV-1a 株的多价、改良活病毒疫苗，并接受不同的 BVDV-1b 株的挑战，以确定疫苗对这些异源病毒株的效力和免疫持续时间。接种疫苗的小牛在所有给药途径中均免受 BVDV-1b 病毒引起的呼吸道疾病的影响，表现为临床症状明显减少、直肠温度较低、病毒脱落减少和白细胞计数增加。BVDV-1a 疫苗在小牛中引起了针对每种 BVDV-1b 挑战株的有效保护，免疫持续时间至少为 6 个月。
