Synergy of therapeutic heterologous prime-boost hepatitis B vaccination with CpG-application to improve immune control of persistent HBV infection.

Therapeutic vaccination against chronic hepatitis B must overcome high viral antigen load and local regulatory mechanisms that promote immune-tolerance in the liver and curtail hepatitis B virus (HBV)-specific CD8 T cell immunity. Here, we report that therapeutic heterologous HBcore-protein-prime/Modified-Vaccinia-Virus-Ankara (MVA-HBcore) boost vaccination followed by CpG-application augmented vaccine-induced HBcAg-specific CD8 T cell-function in the liver. In HBV-transgenic as well as AAV-HBV-transduced mice with persistent high-level HBV-replication, the combination of therapeutic vaccination with subsequent CpG-application was synergistic to generate more potent HBV-specific CD8 T cell immunity that improved control of hepatocytes replicating HBV.