Eastern Health, Victoria, Australia; Research & Molecular Development, Victorian Infectious Diseases Reference Laboratory, 10 Wreckyn St, North Melbourne, VIC 3051, Australia. Electronic address: Uma.Devi@mh.org.au.
Antiviral therapy for chronic hepatitis B (CHB) has improved the outcome of patients. However, due to the multiple selection pressures of different nucleos(t)ide analogue, drug resistant HBV variants have emerged. Because of the arrangement of overlapping reading frames in HBV genome, these variants not only have clinical implications such as drug resistance, but also the potential to pose public health issues via vaccine escape. Whilst emergence of these variants cannot be prevented, careful selection and institution of the appropriate rescue anti viral therapy based on high genetic barrier and high potency should minimize this outcome.