title: Efficacy of four commercially available multivalent modified-live virus vaccines against clinical disease, viremia, and viral shedding in early-weaned beef calves exposed simultaneously to cattle persistently infected with bovine viral diarrhea virus and cattle acutely infected with bovine herpesvirus 1.
abstract: OBJECTIVE
  To evaluate the efficacy of 4 commercially available multivalent modified-live virus vaccines against clinical disease, viremia, and viral shedding caused by bovine viral diarrhea virus (BVDV) and bovine herpesvirus 1 (BHV1) in early-weaned beef calves.
  
  
  METHODS
  54 early-weaned beef steers (median age, 95 days).
  
  
  METHODS
  Calves were randomly assigned to 1 of 5 groups and administered PBSS (group A [control]; n = 11) or 1 of 4 commercially available modified-live virus vaccines that contained antigens against BHV1, BVDV types 1 (BVDV1) and 2 (BVDV2), parainfluenza type 3 virus, and bovine respiratory syncytial virus (groups B [11], C [10], D [11], and E [11]). Forty-five days after vaccination, calves were exposed simultaneously to 6 cattle persistently infected with BVDV and 8 calves acutely infected with BHV1 for 28 days (challenge exposure). For each calf, serum antibody titers against BVDV and BHV1 were determined before vaccination and before and after challenge exposure. Virus isolation was performed on nasal secretions, serum, and WBCs at predetermined times during the 28-day challenge exposure.
  
  
  RESULTS
  None of the calves developed severe clinical disease or died. Mean serum anti-BHV1 antibody titers did not differ significantly among the treatment groups at any time and gradually declined during the study. Mean serum anti-BVDV antibody titers appeared to be negatively associated with the incidence of viremia and BVDV shedding. The unvaccinated group (A) had the lowest mean serum anti-BVDV antibody titers. The mean serum anti-BVDV antibody titers for group D were generally lower than those for groups B, C, and E.
  
  
  CONCLUSIONS
  Results indicated differences in vaccine efficacy for the prevention of BVDV viremia and shedding in early-weaned beef calves.
authors.forename: Manuel F
authors.initials: MF
authors.lastname: Chamorro
authors.forename: Paul H
authors.initials: PH
authors.lastname: Walz
authors.forename: Thomas
authors.initials: T
authors.lastname: Passler
authors.forename: Roberto
authors.initials: R
authors.lastname: Palomares
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Newcomer
authors.forename: Kay P
authors.initials: KP
authors.lastname: Riddell
authors.forename: Julie
authors.initials: J
authors.lastname: Gard
authors.forename: Yijing
authors.initials: Y
authors.lastname: Zhang
authors.forename: Patricia
authors.initials: P
authors.lastname: Galik
mesh_terms: D000375:Aging; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000517:prevention & control* / Q000821:virology; D002417:Cattle; D003967:Diarrhea / Q000517:prevention & control / Q000662:veterinary; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology*; D007242:Herpesvirus 1, Bovine / Q000276:immunology; D008297:Male; D014611:Vaccination / Q000662:veterinary; D014613:Vaccines, Attenuated; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia / Q000662:veterinary*; D017201:Virus Shedding; D014886:Weaning
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines