Inhibition of coronavirus 229E replication by actinomycin D

The yields of human coronavirus 229E grown in L132 cells were markedly inhibited by actinomycin D, the 50% inhibitory dose being 0.1 micron/ml. Inhibition was maximal during the early phase of virus replication, did not appear to involve viral RNA synthesis per se, and was shown to be dependent on the input multiplicity of infection.