Recombinant feline interferon omega (RFeIFN-ω), sold under the brand name Virbagen Omega among others, is a recombinant version of a cat interferon alpha.
[1] It is used to treat a range of viral diseases in cats and dogs, including canine parvovirus, feline leukemia virus (FeLV), and feline immunodeficiency virus (FIV) in many countries.
RFeIFN-ω is produced in silkworm larvae using a baculovirus vector.
[2] Side effects include hyperthermia and decrease in white blood cell count.
[1] As the approved regimen is very costly, RFeIFN-ω has been experimentally used via other routes, including topical and oral protocols.