Abstract :
More than 5% of the population are chronic carriers of hepatitis B virus (HBV). Hepatitis B and its complications are among major problems worldwide. Immunization is the best method for prophylaxis. This study was conducted to evaluate the efficacy of the HBV vaccine and to measure the titer of antibody against HBsAg after vaccination. We collected serum samples from 100, 12 to 16-month-old infants who were vaccinated for three times (based on the recommendations of the Iranian Expanded Program on Immunization) during 1997. Serum samples were collected from individuals 3 – 6 months after the third vaccination and were tested for antibody against HBsAg using an ELISA technique. Of 100 infants tested, 81 had antibody against HBsAg after immunization. These included 40 (42%) males and 41 (51%) females. The average titer of antibody production against HBsAg was 1,236 mIU/dL in males and 1,282 mIU/dL in females (overall: 1213 mIU/dL). The lower and the upper limit of antibody production was 100 and 1,600 mIU/dL, respectively. The lower and the upper limits were seen in 15-monthold infants. The efficacy of the HBV vaccine (Heberbiovac-Hb) in 12 to 16-month-old infants was therefore, 81%. Our study revealed results far different from those mentioned in textbooks and indicated that a high percentage of infants do not respond appropriately after vaccination against HBV.
