RESUMEN
Brucellosis is an infectious and contagious disease that profoundly impacts public health. However, in many countries, disease prevention is restricted to the vaccination of calves, and there is no prophylactic strategy for pregnant heifers and cows. The aim of this study was to evaluate the safety of the rough strain vaccine against brucellosis in pregnant cattle. Crossbred cows (N = 96) at three gestational periods (early, mid, or late pregnancy) were randomly allocated into the vaccine treatment group or to the control group. We then compared the percentage of pregnancies reaching full term, live calves 60 days after delivery, and seropositive calves. There was no effect of vaccination in any of the gestational periods on the evaluation endpoints. In conclusion, vaccination against brucellosis with the rough strain is safe for pregnant cattle at all gestational periods.