Inhibition of influenza RNA synthesis by virazole (ribavirin).

Virazole (ribavirin) inhibits the RNA synthesis of an influenza A virus (fowl plague). Neither virion RNA nor complementary RNA are produced. Although the effect of virazole can be counteracted by guanosine the inhibitor does not interfere with the uptake or incorporation of labelled guanosine into chick embryo cells, nor does replacement of glucose by mannose amplify the effect of virazole. Thus virazole seems not to act via an interference with the GTP pool. Synthesis of Semliki Forest virus RNA is not affected by virazole.