Protection of the bovine fetus from bovine viral diarrhoea virus by means of a new inactivated vaccine.

A model is described for the validation of vaccines designed to protect the bovine fetus from bovine viral diarrhoea virus (BVDV). The fetopathic nature of the challenge strain of virus was confirmed and the method used to test a commercial vaccine (Bovidec) developed from a Compton prototype. Heifers were vaccinated two or three times about the time of impregnation and challenged when they were between 25 and 80 days of gestation. There was no evidence of a viraemia in the heifers after the challenge, or of infection with BVDV of 13 liveborn calves or two aborted fetuses.