PSEUDORABIES VIRUS MUTANTS INCAPABLE OF PRODUCING GLYCOPROTEIN X

摘要

Herpesvirus vaccine comprises a properly incapacitated virus having a deletion for a gene encoding a secreted glycoprotein which allows the serological distinction between the vaccine virus and its wild-type progenitor virus. The virus may be e.g. pseudorabies virus, Marek's disease virus or infectious bovine rhinotracheitis virus. Distinguishing between animals infected with a virus and animals vaccinated with a virus comprises vaccinating animals susceptible to the virus with a vaccine comprising the virus having a deletion for at least one gene encoding an antigen of the wild-type progenitor virus, and then serologically distinguishing between such vaccinated animals and those infected with virulent virus without sacrificing the animal.