|Bolin, Steven - Steve|
Submitted to: American Association of Veterinary Laboratory Diagnosticians
Publication Type: Abstract Only
Publication Acceptance Date: 10/28/1995
Publication Date: N/A
Technical Abstract: Bovine viral diarrhea virus (BVDV) can be segregated into two types, Type 1 and 2 based on genotypic and antigenic differences. The microtiter virus neutralization test (VNT) in cell culture has been widely used to detect BVDV antibodies. BVDV strains used in the VNT have usually been Type 1 BVDV strains (Singer and NADL). Thus, serosurveys have detected predominately Type 1 BVDV antibodies. The purpose of this study was to detect Type 1 and 2 BVDV antibodies using several strains of each Type, including both cytopathic (CP) and noncytopathic (NCP) strains. Positive control sera included one from USDA NVSL prepared in an animal sequentially exposed to multiple Type 1 strains, and serum from a calf exposed sequentially to Type 1 and 2 strains. Serums were also obtained from calves: (1) receiving modified-live virus vaccine (NADL strain); and (2) receiving an inactivated vaccine (Singer strain). Serums were from day 42 (MLV given once at day 0,, and inactivated vaccine given twice on day 0 an 28). Results indicate the range of neutralizing antibody titers to 13 Type 1 and 3 Type 2 BVDV CP strains were: (1) NVSL 440 BDV 7801, Type 1 antibodies: 512 to 4096; Type 2 antibodies: 64 to 256; (2) Calf no. 844 NADC, Type 1 antibodies: 1024 to 8192; Type 2 antibodies: 4096 to 8192. For NVSL 440 BDV 7801 serum (prepared against Type 1 viruses only) there was approximately 8-fold less antibody titer to Type 2 than to Type 1. Antibody titers in vaccinated calves to the Type 1 and 2 BVDV strains are represented by: (1) Calf 1-1, MLV (Type 1, 128 to 1024; Type 2, 4 to 16); and (2) Calf 1-12, inactivated (Type 1, 256 to 1024; Type 2, 64 to 128). Antibody titers were higher to homologous BVDV Type 1 strains with lower levels against the Type 2 strains.