Abstract
The occurrence of homologous interference in the replication of infectious pancreatic necrosis virus was demonstrated after successive passages of partially purified virus at high input multiplicities in trout and Atlantic salmon cell cultures. Pretreatment of cell cultures with interfering virus inhibited the replication of homologous standard infectious virus but not unrelated viruses. The ability of infectious pancreatic interfering virus to interfere with homologous virus was abolished with UV irradiation, immune serum, and freeze-thawing.