Stimulated growth of respiratory syncytial virus in the presence of actinomycin D

The growth of respiratory syncytial virus in HeLa cells, during the first day, was stimulated tenfold in the presence of 0.05 to 0.5 µg/ml of actinomycin D despite visible cytotoxicity of the drug over this range of concentrations. However, the ultimate virus yield, after three days, was suppressed. It is concluded that, as with other pseudo- and paramyxoviruses, the growth of respiratory syncytial virus is not dependent on the production of a new cell-coded protein.