Dose-dependent effects of oral acyclovir in the incubation period of varicella.

Dose of acyclovir (ACV) and clinical features of varicella were evaluated in 65 household contacts (0.8-9 y) who received oral ACV (5-80 mg/kg daily in four divided doses) during the latter half of the incubation period of varicella. The severity of the disease was compared with that of 23 children who did not receive ACV. Infection was confirmed by a fluorescent antibody to membrane antigen assay. The antibody titers and the rate of apparent infection increased as the dose of ACV administered decreased. The number of skin lesions in patients who received ACV was significantly reduced when compared to the control group. These data suggest dose-dependence of ACV for modification of varicella during secondary viremia in the incubation of the disease.