Interference activity of bovine herpes virus 1 strains against Aujeszky's disease virus in cell cultures.

The interference-inducing activity of different low- and high-virulence strains of bovine herpes virus 1 (BHV-1) against Aujeszky's disease virus was studied by a parallel titration on permissive and non-permissive cell culture. The low-virulence BHV-1 strains possessed better interference-inducing activity than the high-virulence strains. An interference blocking test (IBT) was developed for the detection of BHV-1 antibodies in bovine sera.