RESUMEN
In Uzbekistan and Moldova 542 children born of HBsAg carriers were immunized against hepatitis B (with vaccine Engerix B according to the immunization schedule of 4 injections). Anti-HBs antibodies in protective titers were detected by EIA and RIA techniques in 76.7% of children aged 4-5 months after the 3rd injection, in 95.7% of children aged 15-16 months and in 90.0% of children aged 2-2.5 years after the 4th (booster) injection. In the control group (117 nonimmunized children born of HBs carriers) observed during the same period anti-HBs antibodies were detected significantly less frequently (in 7.3%, 11.6% and 12.9% of these children respectively). 1-2 months after the course of immunization was completed 74.1% of the immunized children had high anti-HBs antibody titers (exceeding 1000 IU/ml) with their subsequent decrease by 2-2.5 years of age. In the control group these figures were 27.1% and 29.0% respectively. The index of immunization effectiveness obtained by the comparison of the hepatitis B morbidity rates in both groups was 7.8. No postvaccinal complications were registered.
