The strategies designed to specifically stimulate HBVspecific T cell responses were also not successful [69] [70] [71] . The lipopeptide-based vaccine containing a single cytotoxic T lymphocyte (CTL) epitope derived from HBV nucleocapsid was able to induce a vigorous primary HBV-specific T cell response in naïve subjects [76] . However, in HBV chronic carriers, the vaccine initiated only poor CTL activity and had no effect on viremia or HBeAg/anti-HBe seroconversion [69] . The DNA vaccine expressing small and middle envelope proteins proved to elicit the HBV-specific cellular immune response in chronic HBV carriers, however, this effect was only transient [70] .