Recombinant feline interferon omega (RFeIFN-ω), sold under the brand name Virbagen Omega among others, is a recombinant version of a

cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

interferon alpha The type-I interferons (IFN) are cytokines which play essential roles in inflammation, immunoregulation, tumor cells recognition, and T-cell responses. In the human genome, a cluster of thirteen functional IFN genes is located at the 9p21.3 cyto ...

. It is used to treat a range of viral diseases in cats and dogs, including canine parvovirus,

feline leukemia virus Feline leukemia virus (FeLV) is a retrovirus that infects cats. FeLV can be transmitted from infected cats when the transfer of saliva or nasal secretions is involved. If not defeated by the animal's immune system, the virus weakens the cat's ...

(FeLV), and

feline immunodeficiency virus Feline immunodeficiency virus (FIV) is a '' Lentivirus'' that affects cats worldwide, with 2.5% to 4.4% of felines being infected. FIV was first isolated in 1986, by Niels C Pedersen and Janet K. Yamamoto at the UC Davis School of Veterinary ...

(FIV) in many countries. It is approved to be used by injection under the skin. RFeIFN-ω is produced in

silkworm The domestic silk moth (''Bombyx mori''), is an insect from the moth family Bombycidae. It is the closest relative of '' Bombyx mandarina'', the wild silk moth. The silkworm is the larva or caterpillar of a silk moth. It is an economically ...

larvae using a

baculovirus ''Baculoviridae'' is a family of viruses. Arthropods, among the most studied being Lepidoptera, Hymenoptera and Diptera, serve as natural hosts. Currently, 85 species are placed in this family, assigned to four genera. Baculoviruses are known ...

vector. Side effects include

hyperthermia Hyperthermia, also known simply as overheating, is a condition in which an individual's body temperature is elevated beyond normal due to failed thermoregulation. The person's body produces or absorbs more heat than it dissipates. When extreme ...

and decrease in white blood cell count. These effects tend to be mild and transient. It is a

immunostimulant Immunostimulants, also known as immunostimulators, are substances (drugs and nutrients) that stimulate the immune system by inducing activation or increasing activity of any of its components. One notable example is the granulocyte macrophage colon ...

in the

interferon Interferons (IFNs, ) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten t ...

family. The feline interferon "omega" gene was first cloned in 1992. It was first produced in silkworms by Ueda and coworkers in 1993. The protein is around 60% identical to human alpha interferons, but the Ueda team deemed it an "omega-type" interferon due to some motifs. Phylogenic analysis in 2007 puts it as an alpha-type interferon.

Research

As the approved regimen is very costly, RFeIFN-ω has been experimentally used via other routes, including topical and oral protocols. RFeIFN-ω has also been used off-label to treat other viral infections. It has also been tried on cancer cell cultures. RFeIFN-ω, delivered topically, is ineffective against feline upper respiratory tract disease caused by

feline calicivirus ''Feline calicivirus'' (FCV) is a virus of the family '' Caliciviridae'' that causes disease in cats. It is one of the two important viral causes of respiratory infection in cats, the other being '' Felid alphaherpesvirus 1''. FCV can be isol ...

Notes

References

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