Hepatitis B Booster Study in Adolescence

This study looks at protection in 10-11 and 15-16 year olds, immunized as infants with Hepatitis B (HB) vaccine to see if they still have residual protection against Hepatitis B disease. Adolescents will be invited to have a blood test and those without a minimal level of protection (antibody titer) will be offered a "test" vaccination to see if they still have capacity to recall an immune response. About one month later they will get another blood test to see if a booster response occurred. A few participants will have lost protection (no booster response) and will be offered a second HB vaccination to restore protection. Results of this study could influence the way in which children in British Columbia (BC) are immunized against HB disease.