Novel BVDV-2 mutants as new candidates for modified-live vaccines.
Protection against Bovine viral diarrhea virus (BVDV) type 2 infection of commercially available vaccines is often limited due to marked genetic and antigenic differences between BVDV types 1 (BVDV-1) and 2 (BVDV-2). Therefore, the immunogenicity of selected BVDV-1 and BVDV-2 mutants derived from infectious full-length cDNA clones and their use as modified-live vaccine candidates against challenge infection with a virulent heterologous BVDV-2 field isolate were investigated. Deletion mutants of BVDV-1 and BVDV-2 lacking a part of the N(pro) gene (BVDV-1DeltaN(pro)/BVDV-2DeltaN(pro)) were used as well as a packaged replicon with a deletion in the structural core protein encoding region (BVDV-2DeltaC-pseudovirions). The 25 calves used in this vaccination/challenge trial were allocated in five groups (n=5/group). One group received BVDV-1DeltaN(pro) (1 shot), one group BVDV-2DeltaN(pro) (1 shot), one group received both, BVDV-1DeltaN(pro) and BVDV-2DeltaN(pro) (1 shot), and one group was immunised with the BVDV-2DeltaC-pseudovirions (2 shots). The fifth group served as non-vaccinated control group. All groups were challenged intranasally with the BVDV-2 strain HI916 and monitored for signs of clinical disease, virus shedding and viremia. All tested BVDV vaccine candidates markedly reduced the outcome of the heterologous virulent BVDV-2 challenge infection showing graduated protective effects. The BVDV-2DeltaN(pro) mutant was able to induce complete protection and a "sterile immunity" upon challenge. Thus it represents a promising candidate for an efficacious future live vaccine.
Zemke
Johanna
J
Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald - Insel Riems, Germany.
König
Patricia
P
Mischkale
Katrin
K
Reimann
Ilona
I
Beer
Martin
M
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001831:Body Temperature / Q000276:immunology; D002417:Cattle; D002460:Cell Line; D030242:Diarrhea Virus 2, Bovine Viral / Q000235:genetics* / Q000276:immunology*; D005260:Female; D030243:Hemorrhagic Syndrome, Bovine / Q000517:prevention & control*; D007962:Leukocytes / Q000821:virology; D009154:Mutation; D009666:Nose / Q000821:virology; D017422:Sequence Analysis, DNA; D014759:Viral Envelope Proteins / Q000235:genetics; D019562:Viral Load; D014765:Viral Vaccines / Q000276:immunology*
D000914:Antibodies, Viral; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C076551:gp53, bovine viral diarrhea virus