Experiences with two BHV1 marker vaccines

Abstract

Both marker vaccines tested were deleted vaccines, one had a gG, the other a gE deletion. The gG deleted vaccine was inactivated the gE deleted vaccine had a live and an inactivated form. The object of the trial was to evaluate these vaccines in heifers and calves. Twenty young heifers were used for the inactivated deleted vaccines and 16 four week old female calves for the gE deleted live vaccine. Animals were three times vaccinated, first at 4 and 7 week intervals and again six or ten months later. Challenge was conducted by placing seronegative fields virus inoculated animals between the vaccines. Neither vaccine was able to prevent infection with filed virus, long virus shedding periods and the establishing of latency. Local reactions were insignificant concerning general health. The humoral response was better after the seven week interval but the protection form clinical disease was not. The live vaccine led to a better protection from clinical disease than the inactivated vaccines.