Production lots of a live influenza vaccine made of strains A/47/T (N1H1), A/47/6/2 (H3N2), and B/60/32 were used for vaccination of 3663 children aged from 5 to 14 years inoculated twice with monovaccines, a trivaccine made of the above strains, or placebo. Both mono- and polyvaccine were practically areactogenic. An average per cent of subjects with a significant rise in antibody titres to the respective three antigens was 60%. The efficacy of the vaccination was 31.0-42.8% for monopreparations and 36.3% for the trivaccine. The studies showed the possibility and expedience of using for children the live influenza vaccine in the form of a polyvalent preparation including current influenza type A and B viruses.