Now preventive maintenance of flu by means of vaccination is conventional and is supported by experts of all world. To check presence of trypsin-like proteinase and its inhibitor in anti-flu and other vaccines and in immune biological blood preparations of domestic and foreign manufacture. In work following commercial preparations have been used:" Interferon leukocytic human"," the Immunoglobulin of human placental, donor 10 %, a gonococcal vaccine a herpetic vaccine (Odessa), vaccines for preventive maintenance of a flu, a season 2002/2003 -"Influvac" which consists of hemagglutinins and a neuraminidase of a virus of a flu, strains: ÐÂÂÂÃâÃÂ/Moscow/10/99 (H3N2), ÐÂÂÂÃâÃÂ/New Caledonia/20/99 (H/N), B/Hong Kong/330/2001, "Fluarix" which consists of hemagglutinins of strains (H1N1) A/New Caledonia (H3N2), ÐÂÂÂÃâÃÂ/Panama Shandont 17/97 and "Vaxigrip" which consists of three strains of a flu virus, a vaccine for preventive maintenance of a hepatitis A - "Avaxim", a blood preparation received from a heparin (the antifactor of Ha) - "Fraxiparine", a preparation from a blood of calfs for a hemodialysis - "Solcoseryl". Preparations were investigated before the termination of a period of validity. Results: Work is devoted to study presence of components of a cell-owner and its inhibitor in vaccines and blood preparations and to define presence trypsin-like proteinase and its inhibitor in vaccines and blood preparations. It is revealed that anti influenza vaccines (influvac, vaxigrip, fluarix), herpetic and tularemic vaccines contained an inhibitor of trypsin-like proteinase in considerable quantity. Commercial preparations from a human donor blood (an immunoglobulin, interferon, fraxiparine and solcoseryl) contained as trypsin-like proteinase, and its inhibitor. The immunoglobulin contained in 4,0 times more inhibitor, than interferon. Conclusions: Hence, the modern vaccines applied to prophilaxis and treatment, are insufficiently cleared.Presence of cellular components (enzymes and inhibitors) could lead to allergization and follow complication which is not very known.