The present invention is directed to human influenza virus binding substance containing at least one oligosaccharide chain, which comprises a terminal NeuNAcα6 linked to: (a) a linear or branched polylactosamine type structure consisting of at least three lactosamine residues, a linear sequence optionally containing one or two α3-linked fucose residues in a non-sialylated lactosamine, a branched structure optionally carrying one or more additional NeuNAcα-residues at a terminal position in a branch, and/or (b) a linear or branched structure with two lactosamine and one lactose residue, a linear structure in addition containing one or two α3-linked fucose residues in a non-sialylated lactosamine or lactose, a branched structure optionally carrying one additional NeuNAcα-residue in a terminal position of the branch, or an analog or derivative of said oligosaccharide chain for use in binding of human influenza virus.