Isolation of bromovinyldeoxyuridine-resistant strains of herpes simplex virus and successful chemotherapy of mice infected with one such strain by using acyclovir.

Several strains of herpes simplex virus which were resistant to bromovinyldeoxyuridine were isolated by passaging the virus in the presence of the drug in tissue culture. The resistance of the majority of isolates was accounted for by their reduced ability to induce the enzyme thymidine kinase. These strains were co-resistant to acyclovir, but showed reduced pathogenicity in mice. However, another type of bromovinyldeoxyuridine-resistant virus was isolated which induced normal levels of thymidine kinase and retained virulence for mice. This resistant virus was sensitive to acyclovir and was successfully treated using oral acyclovir therapy.