Inhibition of Arc-like Fragments and Immature Forms of Vaccinia Virus by Methisazone 1

Abstract

Summary

HeLa and HEp 2 cells were infected with vaccinia virus for 1 hr and then treated with methisazone in a concentration of 40 μM. Electron microscopic observations of the cells were carried out 6 and 9 hr after infection. In controls without methisazone, arc-like fragments of virus and immature virions were found at 6 hr after infection. After 9 hr, in addition to fragments and immature forms, there were numerous clusters of mature viral particles. In cells treated with methisazone, fragments, immature forms, and mature virions were not found. These observations indicate that the antiviral action of methisazone occurs at a stage preceding visible viral fragments or particles.