japan or as wellferon u00ae interferon alpha nl ins available from the glaxo wellcome ltd london great britain or a consensus alpha interferon such as those described in u s pat nos 4 897 471 and 4 695 623 especially examples 7 8 or 9 thereof and the specific product available from amgen inc newbury park calif or interferon alpha n3 a mixture of natural alpha interferons made by interferon sciences and available from the purdue frederick co norwalk conn under the alferon tradename the use of interferon alpha 2a or alpha 2b is preferred interferons can include pegylated interferons as defined below the terms u201c pegylated interferon u201d u201c pegylated interferon alpha u201d and u201c peginterferon u201d are used herein interchangeably and means polyethylene glycol modified conjugates of interferon alpha preferably interferon alfa 2a and alfa 2b typical suitable pegylated interferon alpha include but are not limited to pegasys u00ae and peg intron u00ae the term u201c ribavirin u201d refers to the compound 1 2r 3r 4s 5r 3 4 dihydroxy 5 hydroxymethyl tetrahydro furan 2 yl 1h 1 2 4 triazole 3 carboxylic acid amide which is a synthetic non interferon inducing broad spectrum antiviral nucleoside analog and available under the names virazole u00ae and copegus u00ae u201c direct acting.