Despite the development of an effective preventive HBV vaccine, the spread of HBV virus continue, particularly in Asia, where the majority of HBV infection is acquired at birth by vertical transmission from mother to baby. HBV vertical transmission has been hypothesized to cause immune tolerance to HBV and thus promoting the subsequent HBV chronicity. Such hypothesis has never been tested and nothing is known about HBV-specific adaptive immune response occurring before birth in baby born form HBV chronically infected mothers. This study aims to gain an understanding of the key components of the immune response to hepatitis B present in cord blood of HBV infected mothers. The characterization of the HBV immune response in utero will provide informations about the cause of HBV chronicity in Asian patients in the management of baby born from HBsAg+ mothers.
