Efficacy of a New Multivalent Vaccine for the Control of Bovine Respiratory Disease (BRD) in a Randomized Clinical Trial in Commercial Fattening Units.

A new multivalent vaccine (DIVENCE^®), containing live gE/tk double-gene-deleted BoHV-1, live-attenuated BRSV, inactivated PI3, and BVDV-1, and BVDV-2 recombinant proteins, has been designed to protect cattle against the main viral pathogens associated with bovine respiratory disease (BRD). The aim of this study was to demonstrate the efficacy of DIVENCE^® against BRD in field conditions. A total of 360 animals from three different farms were included in this study. Calves were randomly distributed to the vaccinated (n = 183; DIVENCE^®) or control (n = 177; phosphate-buffered saline solution) group. All animals received two intramuscular doses (2 mL/dose) three weeks apart of the corresponding product. The entire fattening period (approximately 9 months) was monitored to assess the incidence, severity, and morbidity of BRD as well as administered treatments and growth performance. During this study, a BRSV outbreak was reported in one farm, where vaccinated animals had significantly (p < 0.02) lower morbidity (20.4%) and severity (score of 1.70) compared to the control group (53.70% and score of 2.11). Overall, vaccinated animals had a significantly lower number of cases (p < 0.001; 0.36 vs. 0.64 cases/calf), lower morbidity (p < 0.004; 26.78% vs. 41.24%), and lower antimicrobial treatments (p = 0.01; 33.3% vs. 57.4%) than control animals. Vaccinated animals presented significantly (p = 0.01) higher carcass weight than controls (6.58 kg). Vaccination with DIVENCE^® at the beginning of the fattening period decreased the incidence and morbidity of BRD following a BRSV outbreak. Additionally, the overall incidence and morbidity of BRD throughout the entire fattening period were reduced across farms. Thus, DIVENCE^® can improve economic outcomes in fattening units by reducing antibiotic treatments and enhancing performance.