A method of treating an avian influenza viral infection using a poly ICLC formulation with improved therapeutic efficacy is disclosed. The poly ICLC is encapsulated within liposomes which provides a drug delivery system with slow sustained release characteristic and which has the ability to target the drug to sites of viral infection without causing systemic burden to normal tissues, thereby enhancing the immunological and biological activities of poly ICLC. This poly ICLC formulation has been found to be particularly effective in treating an avian influenza viral infection and in particular, an avian H5N1 influenza viral infection.
