  In this paper, we investigate the dynamics of hepatitis B virus infection
taking into account the implementation of combination therapy through
mathematical modeling. This model is established considering the interplay
between uninfected cells, infected cells, capsids, and viruses. Three drugs are
considered for specific roles (i) pegylated interferon (PEG IFN) for immune
modulation, (ii) lamivudine (LMV) as a reverse-transcriptase inhibitor, and
(iii) entecavir (ETV) to block capsid recycling. Using these drugs, three
combination therapies are introduced, specifically CT PEG IFN plus LMV, CT PEG
IFN plus ETV, and CT PEG IFN plus LMV plus ETV. As a result, when LMV is used
in combination therapy with PEG IFN and ETV, the impacts of ETV become
insignificant. In conclusion, if the appropriate drug effectively inhibits
reverse transcription, there is no need for an additional inhibitor to block
capsid recycling.
