Fetal protection against bovine viral diarrhea virus types 1 and 2 after vaccination of the dam with the DIVENCE vaccine
The aim of this study was to demonstrate the efficacy of DIVENCE, a vaccine against BVDV types 1 and 2 (BVDV-1 and BVDV-2) transplacental infection, following a booster regimen in heifers. Calves of two-to-three months of age were given two intramuscular doses three weeks apart and a booster vaccine six months later. Efficacy was evaluated by means of a challenge with virulent BVDV-1 or BVDV-2 administered via the intranasal route at 85 days of gestation. Clinical signs, serology, viral shedding, WBC count and viremia were monitored after the challenge. Sixty-six days post-challenge, the fetuses were assessed for BVDV to detect transplacental infection. The results demonstrate a reduction in hyperthermia, leukopenia, viral shedding, and viremia in vaccinated animals post-challenge with BVDV-1 and BVDV-2. Most importantly, DIVENCE administered prior to breeding protected 94% of the fetuses against BVDV transplacental infection overall across both challenge trials (BVDV-1 and BVDV-2).