Interferons (IFNs) are antiviral proteins produced in response to viral infection.
There are three types of human interferon: a-IFN, b-IFN, and g-IFN. Recombinant interferons have been produced.
The mode of action of a-IFN and b-IFN is to induce uninfected cells to produce antiviral protein (AVPs) that prevent viral replication.
Interferons are host-cell-specific but not virus-specific.