A safe live recombinant virus as well as a vaccine is produced by the deletion of a portion of the native glycoprotein E (gE) coding region of bovine herpesvirus 1 (BHV-1) followed by the insertion of a plasmid including a foreign functional &bgr;-gal at the gE locus. The deletion of gE gene stably attenuates the virus and serves as an immunological marker differentiating vaccinated animals from infected animals. Moreover, production of &bgr;-gal allows easy assessment of gE&Dgr;3.1IBR&bgr; virus replication in vaccinated animals and serves as a phenotypic marker which distinguishes it from wild type virus replication in infected animals.