A recombinant form of the endogenous cytokine human interferon (IFN) beta-1a, with antiproliferative, antiviral and immunomodulating activities. Upon administration, interferon beta-1a targets and binds to specific type I IFN receptors, which eventually results in the transcription and translation of genes containing an interferon-specific response element and leads to the production of various anti-viral proteins and modulates the production of various immune-modulating proteins. This reduces the production of certain pro-inflammatory cytokines while upregulating the anti-inflammatory cytokine interleukin 10 (IL-10), upregulates the expression of major histocompatibility (MHC) I proteins which allows for increased presentation of peptides derived from viral antigens, and activates CD8+ T cells as well as other immune cells. Endogenous IFN-beta-1a is produced following viral infection and it plays a key role in innate immune response against viral pathogens.