Efficient stabilization of therapeutic hepatitis B vaccine components by amino-acid formulation maintains its potential to break immune tolerance.

Background & Aims: Induction of potent, HBV-specific immune responses is crucial to control and finally cure HBV. The therapeutic hepatitis B vaccine combines protein priming with a Modified Vaccinia virus Ankara (MVA)-vector boost to break immune tolerance in chronic HBV infection. Particulate protein and vector vaccine components, however, require a constant cooling chain for storage and transport, posing logistic and financial challenges to vaccine applications.

Activation of CD4 T cells during prime immunization determines the success of a therapeutic hepatitis B vaccine in HBV-carrier mouse models.

Background & Aims: We recently developed a heterologous therapeutic vaccination scheme (TherVacB) comprising a particulate protein prime followed by a modified vaccinia-virus Ankara (MVA)-vector boost for the treatment of HBV. However, the key determinants required to overcome HBV-specific immune tolerance remain unclear. Herein, we aimed to study new combination adjuvants and unravel factors that are essential for the antiviral efficacy of TherVacB.