Protection of cattle from bovine herpesvirus type I (BHV-1) infection by immunization with individual viral glycoproteins.

The major glycoproteins gI, gIII, and gIV of bovine herpesvirus-1 (BHV-1) were found to induce high levels of antibody in cattle which could neutralize virus and participate in antibody-dependent cell cytotoxicity of BHV-1-infected cells. Immunized animals were fully protected from disease, using a BHV-1/Pasteurella haemolytica aerosol challenge model but not from infection with the virus. Thus, virus could still replicate in the nasal passages of immunized animals, although to a lesser extent than in placebo-treated animals or animals immunized with a commercial killed whole virus vaccine. Systemic spread of the virus in immunized animals did not appear to occur since there was not a dramatic alteration of leukocyte function following challenge. These results suggest that any one of the three major BHV-1 glycoproteins may be useful as a subunit vaccine either individually or in combination.