ART4 and infection: However, it is not yet clear whether this virucidal activity results from the PACs-A2′s “coating” of the entire viral envelope glycoprotein array or whether it is due to the binding of PACs-A2 to specific viral glycoproteins; as observed for the whole cranberry extract, the binding of PACs-A2 to viral glycoproteins may compromise their essential functions in the early stages of infection.