Rescue of a Vaccinia Virus Mutant Lacking IFN Resistance Genes K1L and C7L by the Orf Virus.

Type 1 interferons induce the upregulation of hundreds of interferon-stimulated genes (ISGs) that combat viral replication. The orf virus (ORFV) induces acute pustular skin lesions in sheep and goats and can reinfect its host, however, little is known of its ability to resist IFN. Vaccinia virus (VACV) encodes a number of factors that modulate the IFN response including the host-range genes and .