The clinical studies reviewed here indicated the usefulness of topical application of Human-fibroblast-derived (Beta) interferon (Hu1FN-B) in treatment of Adeno-8 Epidemic-keratoconjunctivitis. A week treatment with 2-5 x 10(5) reference units daily doses, starting early as possible, reduced the length of the disease from 22 day to a week, and almost totally prevented the appearance of subepithelial keratitis which occurred in 57% of the control group. Possibly interferon should be given also prophylactically to individuals exposed to contagion. Our results encourage further investigation on the Hu1 FN-B use as a drug for treatment and prevention of viral infection.