A clinical and laboratory examination of 62 children aged 10—17 years vaccinated against hepatitis B according to the standard scheme (0—1—6 months) in the first year of life strictly according to the National Calendar of preventive vaccinations in a standard dose (10 micrograms of recombinant HBsAg) with a monocomponent vaccine was carried out.The majority of children (58%) had indicators of seroconversion of HBsAg — anti-HBs-antibodies. This indicates the fact of long-lasting Grund immunity — 10—17 years after timely 3-fold immunization against hepatitis B according to the standard scheme at a standard dose (10 mcg of recombinant HBsAg in the first year of life in the absence of Wooster immunization (revaccination) in subsequent age periods, including children with a burdened premorbid background (87.1% among those observed). Since among those observed were children with invasive medical interventions (50%), the established fact reflects the protective effect of standard Grund immunization even in children at risk — with a positive parenteral history. At the same time, the total assessment of serological and molecular biological results found that after triple immunization against hepatitis B according to the standard scheme in the first year of life, out of 62 children aged 10—17 years, the proportion of seronegative was 42%. Low levels of antibodies (10—100 IU/l) were detected in 43% of cases, high (100—1000 IU/l) — in 15% of cases. No child had an antibody level exceeding >1000 IU/l. These results require the development of new approaches to immunization of children against hepatitis B with mandatory revaccination at an older age.