Evidence for the genetic basis of non-response in mice.

In the murine model the immune response to both the hepatitis B envelope and nucleocapsid antigens are linked to the MHC class II haplotype but they are independently restricted. Although in a human outbred population non-response is less likely, the host genetic environment may be important in determining the level of response to vaccine and inclusion of antigens apart from the S antigen may improve protection. The inclusion of HBcAg in vaccine remains controversial since, despite its high immunogenicity, the Th-cell response to this antigen may have a role in the down regulation of the immune response to HBV so promoting persistence.