Development of immune system proceeds throughout the entire period of the childhood and endures a number of critical stages which need to be considered at an assessment of a state of health, formation of preventive programs and purpose of treatment at diseases. At the present stage medical practice has to solve a problem of simultaneous increase of efficiency of etiotropny therapy of infections, decrease in collateral and undesirable reactions, increases in functional activity of own immune system and rates of restoration of immunological violations with use of methods and the preparations which efficiency is based on positions of evidential medicine.