Immune response and protection of neonatal, colostrum-fed calves with modified live, intranasal, tri-valent vaccine using an experimental challenge with virulent bovine respiratory syncytial virus

Abstract

Bovine respiratory syncytial virus (BRSV) is major viral con­tributor to bovine respiratory disease (BRD). BRD is a major cause of morbidity and mortality in all classes of cattle but par­ticularly young beef and dairy calves. Passive antibodies not only help protect the calf against infection, but may interfere with the immune responses following vaccination. The objective of this study was to evaluate the efficacy and immune response of an intranasal modified live virus (MLV) trivalent vaccine in the presence of well-defined maternal passive immunity.