Recently, a novel therapeutic approach for treatment of chronic hepatitis B in a woodchuck model was described. The therapy combined the antiviral treatment with immunization with plasmid DNA and antigen-antibody immunogenic complex vaccines together [112] . DNA vaccines are considered to stimulate both humoral and cellular immune response, polarizing T cells in the direction of Th1 response [122] . Immunization of the naïve woodchucks with the plasmids encoding WHV core and preS2/S genes (pWHcIm and pWHsIm, resp.) induced the lymphoproliferative responses against the antigens and provided a protection against WHV challenge [123] . In addition, the DNA vaccine expressing HBsAg proved to elicit the vigorous T cell responses in chronic HBV carriers, however, this effect was only transient [70] . The HBsAg/anti-HBs IC vaccine is currently under the investigation in chronic HBV patients [77] [78] [79] .