Vaccination against Vibrio (Campylobacter) fetus infection in sheep in late pregnancy.

A single injection of vaccine containing disrupted formol-killed Vibrio (campylobacter) fetus var intestinalis serotype V was shown to give good protection against abortion from an oral challenge of the same serotype administered simultaneously. Protection was also afforded by vaccination at the time of the first abortion in sheep infected orally one month previously. These results suggest that vaccination subsequent to an abortion might be of value in preventing a proportion of further abortions.