Abstract: The object of the invention are monoclonal antibodies against hemagglutinin of H5-serotype influenza viruses selected from the group comprising G-1-31-22, G-2-14-10, G-5-32-5, G-6-42-42, G-7-24-17 and G-7-27-18, having a broad application in immunoprophyiaxis and immunotherapy of infections evoked by H5-serotype influenza viruses in humans and animals. The invention also provides hybridomas producing said antibodies, as well as compositions and diagnostic kits containing said antibodies for the detection and typing of H5-serotype influenza viruses and antibodies against H5-serotype influenza viruses in biological samples.

Abstract: The invention relates to an influenza viruses hemagglutinin protein as a vaccine antigen against influenza viruses, in particular to a protein being a fragment of H5 hemagglutinin from highly pathogenic avian influenza virus (HPAIV) H5N1 strain, expressed in a bacterial expression system. The protein according to the invention is a potential ingredient of an anti-HPAIV H5N1 vaccine, administered to chickens parenterally or through mucous membranes in the presence of adjuvants. The object of the invention is also a method of obtaining the vaccine protein.