Serological effect of two concurrent IBRV, BVDV, BRSV, PI3V, and Mannheimia haemolytica vaccination protocols and time interval between the first and second dose on the subsequent serological response to the BRSV and M. haemolytica fractions in suckling beef calves

Abstract

This study was conducted to compare the serologic response of suckling beef calves to the bovine respiratory syncytial virus (BRSV) and Mannheimia haemolytica fractions of 2 bovine respiratory disease (BRD) vaccination protocols when the second dose was given 153 days after the first dose. Calves in 1 group were vaccinated with intranasal (IN) modified-live virus (MLV) 3-way BRD vaccine plus separate subcutaneous (SC) injections of MLV bovine viral diarrhea virus (BVDV) type 1 and 2 vaccine and M. haemolytica bacterin-leukotoxoid. Calves in the other group were vaccinated with SC MLV 5-way BRD vaccine combined with M. haemolytica leukotoxoid. On day 153, all calves were revaccinated with SC MLV 5-way vaccine combined with M. haemolytica leukotoxoid. Both calf vaccination protocols stimulated a humoral immune response to the BRSV and M. haemolytica vaccine fractions. Vaccination with IN MLV 3-way BRD vaccine resulted in a significantly (P=0.003) higher initial antibody response to BRSV and a significantly (P=0.006) higher anamnestic response. No differences were seen between groups in initial M. haemolytica leukotoxoid antibody levels. Vaccination with SC MLV 5-way BRD vaccine combined with M. haemolytica leukotoxoid resulted in a significantly (P=0.02) higher anamnestic response to M. haemolytica leukotoxoid.