The impact of culturing conditions (multiplicity of cell culture infection with influenza virus, composition of growth and maintenance nutrient media) for the efficiency of multiplication of cold-adapted reassortant vaccine strains of influenza A and B viruses was evaluated. Soybean hydrolysate protein-based biological additive to nutrient medium provided effective reproduction of influenza A virus in MDCK cells in the presence of 2 microg/ml trypsin. The use of soybean peptone-based stabilizer provided retention of infectious titer of influenza virus grown in MDCK culture after its lyophilization to a level of 8.5 lg EID50/ml.