title: Fetal protection in heifers vaccinated with a modified-live virus vaccine containing bovine viral diarrhea virus subtypes 1a and 2a and exposed during gestation to cattle persistently infected with bovine viral diarrhea virus subtype 1b.
abstract: OBJECTIVE
  To determine efficacy of a modified-live virus (MLV) vaccine containing bovine viral diarrhea virus (BVDV) 1a and 2a against fetal infection in heifers exposed to cattle persistently infected (PI) with BVDV subtype 1 b.
  
  
  METHODS
  50 heifers and their fetuses.
  
  
  METHODS
  Susceptible heifers received a placebo vaccine administered IM or a vaccine containing MLV strains of BVDV1a and BVDV2a administered IM or SC. On day 124 (64 to 89 days of gestation), 50 pregnant heifers (20 vaccinated SC, 20 vaccinated IM, and 10 control heifers) were challenge exposed to 8 PI cattle. On days 207 to 209, fetuses were recovered from heifers and used for testing.
  
  
  RESULTS
  2 control heifers aborted following challenge exposure; both fetuses were unavailable for testing. Eleven fetuses (8 control heifers and 1 IM and 2 SC vaccinates) were positive for BVDV via virus isolation (VI) and for BVDV antigen via immunohistochemical analysis in multiple tissues. Two additional fetuses from IM vaccinates were considered exposed to BVDV (one was seropositive for BVDV and the second was positive via VI in fetal tissues). A third fetus in the SC vaccinates was positive for BVDV via VI from serum alone. Vaccination against BVDV provided fetal protection in IM vaccinated (17/20) and SC vaccinated (17/20) heifers, but all control heifers (10/10) were considered infected.
  
  
  CONCLUSIONS
  1 dose of a BVDV1a and 2a MLV vaccine administered SC or IM prior to breeding helped protect against fetal infection in pregnant heifers exposed to cattle PI with BVDV1b.
authors.affiliation: Pfizer Animal Health, 7000 Portage Rd, Kalamazoo, MI 49001, USA. randy.d.leyh@pfizer.com
authors.forename: Randy D
authors.initials: RD
authors.lastname: Leyh
authors.forename: Robert W
authors.initials: RW
authors.lastname: Fulton
authors.forename: Jacob E
authors.initials: JE
authors.lastname: Stegner
authors.forename: Mark D
authors.initials: MD
authors.lastname: Goodyear
authors.forename: Steven B
authors.initials: SB
authors.lastname: Witte
authors.forename: Lucas P
authors.initials: LP
authors.lastname: Taylor
authors.forename: Bill J
authors.initials: BJ
authors.lastname: Johnson
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Step
authors.forename: Julia F
authors.initials: JF
authors.lastname: Ridpath
authors.forename: Ben P
authors.initials: BP
authors.lastname: Holland
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000517:prevention & control*; D002417:Cattle; D030241:Diarrhea Virus 1, Bovine Viral / Q000276:immunology*; D030242:Diarrhea Virus 2, Bovine Viral / Q000276:immunology*; D005260:Female; D007112:Immunity, Maternally-Acquired; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control / Q000662:veterinary*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control / Q000662:veterinary*; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines