Fetal Protection Against a Type 2 Bovine Viral Diarrhea Virus (BVDV) Challenge in Cattle Vaccinated with a Type I Modified Live BVDV Vaccine

Abstract

Bovine viral diarrhea virus (BVDV) is a continual concern to the cattle industry. Infection with BVDV may result in either acute disease or persistently infected, asymptomatic carriers. Clinical signs of acute disease include depression, anorexia, reproductive failure, respiratory and gastrointestinal disease in cattle. Acute BVDV infection of pregnant cattle at 30-150 days of gestation may result in calves that are persistently infected (PI). Due to intermittent shedding of virus, these calves pose a continual threat to other cattle. In addition, calves may be at risk for superinfection with a different strain of BVDV, resulting in high mortality. The objective of this study was to evaluate the efficacy of a BVDV Type I modified-live virus (MLV) vaccine to protect against the development of persistently infected calves following a homologous Type 2 challenge of heifers.