anti-hbs response and its protective effect in children and adults receiving hepatitis b recombinant vaccine in tehran

background: following who recommendation, hbv vaccination has been integrated into epi program in iran since 1996.   objective: to evaluate the immunogenicity and protective effect of hb vaccine (recombinant heberbiovac ,cuba ) in vaccinated children and adults .   methods: a total of 542 cases (340 children and 202 adults) were vaccinated using a three-doses schedule of zero, one and six month. blood samples were collected before the last injection, one month, one and two years after vaccination.  sera were tested for anti-hbs as indicator of immune response.   results: seroconversion rates for anti-hbs after second dose was 97.9% in children and 87% in adults.  after the third injection this response increased to 100% and 93.7% in children and adults respectively.  the anti-hbs titer decreased after two years in both groups.   conclusion:  general vaccination with heberbiovac vaccine in iran has been successful in provoking immune response and protection against hbv infection.  it seems that the persistence of the produced immunity is higher in children than adults.