Long-term immunity to hepatitis B among a sample of fully vaccinated children in Cairo, Egypt

We assessed the long-term immunity to hepatitis B among 242 Egyptian children aged 6-12 years who had received a full vaccination course in infancy, and investigated the factors associated with immunity. Only 39.4% of the children had protective [>/= 10 IU/L] hepatitis B surface antibody levels [HBsAb]. This proportion decreased with age but the decrease was not statistically significant. The mean level of HBsAb decreased significantly with increasing age [P = 0.026]. A significant negative correlation was found between current age and HBsAb levels [r = -0.31, P = 0.041]. Age and weight-for-age were found to be significant predictors of non-protective HBsAb levels