In vitro susceptibility of varicella zoster virus to adenine arabinoside and hypoxanthine arabinoside.

The in vitro susceptibility of varicella zoster (VZ) isolates to adenine arabinoside (ara-A) and hypoxanthine arabinoside (ara-Hx) was determined in human skin fibroblasts. Using a system in which deamination was inhibited, and using a modified plaque reduction method, the antiviral activities of ara-A and ara-Hx were separated. The plaque inhibitory concentration of ara-A for all VZ isolates tested was 1 to 2 mug/ml and 80 to 100 mug/ml for ara-Hx. A comparison of antiviral activity based upon total plaque suppression gave a rate of 40 to 50:1, in favor of ara-A.