Comparative antiviral efficiency of leukocyte and bacterially produced human α-interferon in rhesus monkeys

Interferons are being tested as antiviral and antitumour agents in man ^1-5, but because of their limited availability, clinical trials have remained inconclusive. Most of the interferon (IFN) preparations tested in man have been derived from human peripheral blood, buffy-coat leukocytes (HuIFN-α)⁶ induced by Sendai virus or from human diploid fibroblastoid cells (HuIFN-β) superinduced with poly(rI)-poly(rC) ⁷. As production of interferon from leukocytes is restricted by the availability of blood donors, and production from cultured cells is a laborious and relatively costly process, the use of recombinant DNA technology may provide the most economical approach to the large-scale production of pure species of human interferon. The testing of such interferons is in its infancy. With the availability of bacterially produced HuIFN-α₂ we have been able to compare its activity against vaccinia virus infection of the rhesus monkey with that of HuIFN-α from leukocyte buffy coats. Here we provide evidence that the two human α-interferons have comparable antiviral activity but that the bacterially produced form has fewer side effects, at least in the rhesus monkey.