Immunologic Response of Hepatitis B Vaccine

This study intended to evaluate the immunologic response to the two hepatitis B virus (HBV) vaccination strategies in previously vaccinated HIV-infected adults at Maharaj Nakorn Chiang Mai Hospital. As a part of HBV prevention program, HBV vaccine has been included in Thailand expanded program on immunization (EPI) since 1992. HBV vaccine has been shown to be safe, effective, and has a prolonged protective immunity to HBV infection. Despite the immunity from HBV vaccination could wane overtime, the previous data in general population revealed that HBV vaccine booster could raise the immune in very well. However, the data about booster effects for HBV vaccine among HIV-infected population who previously received a vaccination during their childhood is lagging. Based on previous data of vaccination response in HIV-infected population, the investigators estimate that the protective antibody will rise up to 60% with HBV vaccine one dose booster versus 90% with 3-dose series. Eighty participants, HIV-infected person who were born after HBV vaccine were born after HBV has been included in Thai EPI without evidence of HBV infection nor protective immunity, will be enrolled to this study (with estimation of 5% loss follow up rate). The participants will be randomized in 1:1. The immune response and vaccine safety will be evaluated at 1,7 and 12 months after the first dose HBV vaccine.