The effect of phosphonoacetic acid on the in vitro replication of varicella-zoster virus.

Phosphonoacetic acid (PAA) was found to inhibit in vitro varicella-zoster virus (VZV) replication. At 100 microng/ml, PAA blocked the development and spread of VZV cytopathology in both growing and contact-inhibited cultures. Formation of virus plaques by infected cells and cell-free virus was effectively blocked at concentrations as low as 25 microng/ml. The development of nuclear and cytoplasmic virus antigens was also inhibited by PAA. Inhibition by PAA suggests that VZV DNA replication, like that of other herpes-viruses, involves a virus-specific DNA polymerase.