Anti-Viral Effect of an Extract of Ganoderma Lucidum

Compositions and methods for the treatment viral infections in organisms, particularly flu virus. The methods and compositions of the disclosure involve the administration to mammals and immune cells of a fucose-containing glycoprotein fraction from Reishi. An extract of G. lucidum induces immune responses that are shown to induce increase survivability in mice injected with lethal does of influenza virus. The effect is increased when the G. lucidum extract is dosed prior to injection of the lethal dose of influenza virus.