Table 2.

Factors explaining the slower selection of drug resistance in HBV when compared with HIV and HCV

1.	Slower turnover of genetic material acting as source of newly produced viral particles in HBV than HIV and HCV.
2.	Constraints in the HBV genome imposed by overlapping reading frames, which do not exist in HIV or HCV.
3.	More effective immune escape for HIV and HCV than for HBV.