Abstract
To develop a vaccination program against bovine viral diarrhea virus (BVDV) using live vaccines, the persistence of antibody following vaccination was estimated. Twenty breeding cattle raised on a dairy farm in the Nemuro district of Hokkaido were used for the experiment. The cattle were divided into the following three groups : ten were vaccinated once with a live BVDV1 vaccine (Group A), five were vaccinated with an inactivated vaccine (containing BVDV1 and BVDV2) after being vaccinated with the live vaccine (Group B), and five were left unvaccinated (Group C). In Group A, both anti-BVDV1 and anti-BVDV2 antibody titers increased and persisted during the three years of the study; no significant difference was recognized between Group A and Group B. Group C showed no significant increase in antibody titer, so natural BVDV infection might not occur during the period. Antibody induced by one-off vaccination with BVDV1 live vaccine was maintained for at least three years. Therefore, the one-off vaccination with BVDV1 live vaccine in the breeding period was an available method for the control of BVDV infection.
