Spectrum of virus inhibition by consensus interferon YM643

The spectrum of viruses inhibited by a genetically engineered consensus int erferon (IFN) YM643 (interferon alfacon-1) was evaluated using a cytopathic effect inhibition assay or plaque inhibition assay for five DNA viruses an d 12 RNA viruses. This activity was compared to that of natural IFN-alpha d erived from Namalwa lymphoblastoid cell line [IFN-alpha (Namalwa)]. The vir uses inhibited by both IFNs were herpesvirus types 1 and 2, human cytomegal ovirus, varicella-zoster virus, vesicular stomatitis virus, yellow fever vi rus, bovine viral diarrhoea virus, Semliki Forest virus, western equine enc ephalitis virus, encephalomyocarditis virus, rhinovirus type A, respiratory syncytial virus, Newcastle disease virus and influenza virus type A (H1N1) . Neither IFN inhibited coxsackie virus B1. reovirus type 3 or vaccinia vir us in the experimental conditions used. The specific activity of YM643 in h uman cells generally ranged from 3.6x10(7) to 2.1x10(9) IU/mg, which was gr eater than that of IFN-alpha (Namalwa), which ranged from 3.1x10(6) to 4.6x 10(8) IU/mg against all sensitive viruses, except human cytomegalovirus and rhinovirus type 1A, which displayed approximately equal sensitivity to bot h IFNs. Significantly, the potency of YM643 against bovine viral diarrhoea virus and yellow fever virus, which were selected to serve as surrogates of hepatitis C virus, equalled or exceeded that of IFN-alpha (Namalwa). These results suggest that the genetically engineered YM643 is more potent than natural IFN-alpha.