THE GLYCOPROTEIN GE OF BOVINE HERPESVIRUS TYPE-1 AND THE NEW MARKER VACCINES

Attenuated and inactivated gE negative marker vaccines against infecti ous bovine rhinotracheitis (IBR) are now available. These vaccines are important tools in bovine herpesvirus type 1 (BHV-1) control programm es because they allow a serological differentiation between vaccinated and naturally infected cattle. BHV-1 glycoprotein gE is present on th e viral envelope. It is not essential for virus replication. This expl ains why gE negative vaccine viruses are still able to replicate both in vitro and in vivo. The biological and biochemical properties of gly coprotein gE are described in this paper. It is involved in virus tran smission by direct cell-to-cell spread and plays a role in neuroinvasi on. These marker vaccines exhibit the same safety and efficacy charact eristics as the previous vaccines. Advantages and disadvantages of thi s kind of vaccine are discussed in the second part of the paper.