Valutazione della viremia in bovini persistentemente infetti da virus della diarrea virale bovina sottoposti a vaccinazione

The infection of pregnant cattle by bovine viral diarrhea virus (BVDV) can result in the birth of immunotolerant and persistently infected (PI) calves, which represent an important source of spread of the virus in the breeding and contribute significantly to the maintenance of a high prevalence of infection. The vaccination of PI animals with BVDV strains antigenically different from persistent strain can induce the production of neutralizing antibodies. Following administration of an inactivated vaccine containing the C86 strain of BVDV to PI cattle, a transient, statistically significant, reduction of viremia was detected. However, the lowering of viremia levels is not high enough to affect the ability to detect PI animals.