A CONVENTIONALLY ATTENUATED GLYCOPROTEIN E-NEGATIVE STRAIN OF BOVINE HERPESVIRUS TYPE-1 IS AN EFFICACIOUS AND SAFE VACCINE

We examined the vaccine properties of a conventionally attenuated bovi ne herpesvirus type I (BHV-1) mutant strain A. This strain has a delet ion that encompasses the glycoprotein E gene and may therefore be used as a marker vaccine. We compared strain A with a commercial live BHV- 1 vaccine B. Calves were intranasally vaccinated with strain A or with vaccine B. Strain A was virtually avirulent for young calves. After c hallenge, vaccinated calves were protected against disease and virus s hedding was considerably reduced. After dexamethasone treatment, strai n A was not recovered, whereas vaccine B and challenge virus were. We conclude that strain A is suitable for inclusion in a vaccine and has the potential advantage of being used as a marker vaccine.