Evidence for the genetic basis of non-response in mice

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