It is believed that the quality and quantity of adaptive immune responses determine the
clinical outcome of hepatitis B infection. It is unknown, however, if combined or alone humoral and
cellular immune responses are needed for viral clearance. We investigate this question using
mathematical models of combined antibody and CD8 T cells responses following adult hepatitis B
infection. We compare the model predictions to data from adult patients discovered during acute
infection and determine the contribution of different immune mechanisms to initial virus decay,
prevention of virus rebound, and virus clearance or persistence.