title: Noncytopathic bovine viral diarrhea virus can persist in testicular tissue after vaccination of peri-pubertal bulls but prevents subsequent infection.
abstract: The objectives of this research were to evaluate the risk of prolonged testicular infection as a consequence of vaccination of peri-pubertal bulls with a modified-live, noncytopathic strain of BVDV and to assess vaccine efficacy in preventing prolonged testicular infections after a subsequent acute infection. Seronegative, peri-pubertal bulls were vaccinated subcutaneously with an approximate minimum immunizing dose or a 10x standard dose of modified-live, noncytopathic BVDV or were maintained as unvaccinated controls. Forty-nine days after vaccination, all bulls were intranasally inoculated with a noncytopathic field strain of BVDV. Semen and testicular biopsies collected after vaccination and challenge were assayed for BVDV using virus isolation, reverse transcription-nested PCR, or immunohistochemistry and the identity of viral strains was determined by nucleotide sequencing of PCR products. The vaccine strain of BVDV was detected in testicular tissue of vaccinated bulls as long as 134 days after immunization. Prolonged testicular infections with the challenge strain were detected only in unvaccinated bulls as long as 85 days after challenge. Whereas vaccination caused prolonged testicular infection in some bulls, it did prevent subsequent infection of testicular tissue with the challenge strain. This research demonstrates that subcutaneous vaccination of naïve, peri-pubertal bulls with a noncytopathic, modified-live strain of BVDV can result in prolonged viral replication within testicular tissue. The risk for these prolonged testicular infections to cause venereal transmission of BVDV or subfertility is likely to be low but requires further investigation.
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849, United States. givenmd@vetmed.auburn.edu
authors.forename: M Daniel
authors.initials: MD
authors.lastname: Givens
authors.forename: Kay P
authors.initials: KP
authors.lastname: Riddell
authors.forename: Paul H
authors.initials: PH
authors.lastname: Walz
authors.forename: Jim
authors.initials: J
authors.lastname: Rhoades
authors.forename: Richard
authors.initials: R
authors.lastname: Harland
authors.forename: YiJing
authors.initials: Y
authors.lastname: Zhang
authors.forename: Patricia K
authors.initials: PK
authors.lastname: Galik
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Brodersen
authors.forename: Anna M
authors.initials: AM
authors.lastname: Cochran
authors.forename: Kenny V
authors.initials: KV
authors.lastname: Brock
authors.forename: Robert L
authors.initials: RL
authors.lastname: Carson
authors.forename: David A
authors.initials: DA
authors.lastname: Stringfellow
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000517:prevention & control*; D002417:Cattle; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology* / Q000302:isolation & purification / Q000502:physiology; D008297:Male; D012741:Sexual Maturation; D013737:Testis / Q000821:virology*; D014611:Vaccination; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia / Q000821:virology; D014779:Virus Replication
chemical_list: D000914:Antibodies, Viral; D014765:Viral Vaccines