Latency and reactivation of a thymidine kinase-negative bovine herpesvirus 1 deletion mutant

A bovine herpesvirus 1 (BHV 1) mutant variant with a deletion in the thymidine kinase (TK) gene was assessed for its ability to establish latency and be reactivated in cattle. After treatment with dexamethasone, reactivated TK- BHV 1 was isolated from one of four cattle that received virus by intravenous inoculation only, and from four of four cattle that received virus by intranasal, intravaginal, and intravenous inoculation. Results prove that TK- BHV 1 will establish latency and can be reactivated in the natural host.