Abortion and shedding of Brucella abortus RB51 in vaginal exudates of vaccinated cows

In this study, Brucella abortus RB51 could be detected in the vaginal exudates of 5 out of 26 aborted cows following vaccination of three dairy cattle herds of 3810 animals including heifers and pregnant and non-pregnant cows by RB51 vaccine. Abortion associated with isolation of RB51 vaccinal strain from recently vaccinated cows in this study served as evidence that the vaccinal RB51 strain was the cause of abortion due to extensive bacterial multiplication and colonization in the uterus of vaccinated pregnant cows