FIELD: medicine, pediatry, virology, vaccines. SUBSTANCE: vaccine strain A/47/New Caledonia /99/156 (H1N1) is a reassortant obtained by crossing epidemic virus A/New Caledonia/20/99 (H1N1) with virus A/Leningrad/134/47/57 (H2N2) as attenuation donor that is harmless for children and its properties ensure a possibility to obtain guaranteed reassortant vaccine strains from newly appearing epidemic viruses. The strain A/47/New Caledonia/99/156 (H1N1) multiplies actively in developing chicken embryos at optimal temperature 33-34 C and shows temperature-sensitivity and cold-adaptation. Reassortant inherited from epidemic virus two genes encoding surface proteins (hemagglutinin and neuraminidase) and six genes encoding nonglycosylated proteins from attenuation donor. The strain A/47/New Caledonia/99/156 (H1N1) is areactogenic for children in age 3-14 years in intranasal route of its administration. Thus, vaccine strain A/47/New Caledonia/99/156 (H1N1) corresponds to biological properties and indices of reactivity to requirements imposing by Pharmacopoeia article 42-3353-97 for live influenza vaccine for intranasal administration in children of age 3-14 years. EFFECT: improved method of preparing, valuable properties. 1 tbl, 1 ex
