Efficacy of Hepatitis-B vaccine in children from 12 to 16 months in Mashad health centers

Background: More than 5% of the people are chronic carriers of HBV. Hepatitis B and its complications are problem around the world . Immunization is the best method for prophylaxis. Objective: This study was conducted in order to evaluate the efficacy of HBV vaccine and to measure the anti-HBs Ag titer. Methods: We collected serum sample from 100 infants, who were 12-16Mo. Old and vaccinated three times (based on Iran immunization program) during 1997. Serum samples were collected from individuals 3-6 month after third vaccination and tested for anti-HBs Ag by ELISA . Findings: Of 100 infants, 81 individuals have anti-HBs Ag after immunization that they were 40 (42.36%) males and 41 (50.62%) females. The average anti-HBs Ag productions in males were 1236 mlu/dl and in females were 1282 mlu/dl. Mean of all samples was 1213 mlu/dl . The lower limit was 100 unit and upper limit was 1600 unit. Lower and upper limits were in infants 15 Mo.Old. The efficacy of HBV vaccine (Heberbiovac-Hb) in infants 12-16 Mo.Old was 81%. Conclusion: The study shows that our results were different from textbooks and high percentage of infants, haven’t anti-HBs Ag after immunization