First-line antiviral therapies for chronic hepatitis B. Entecavir (ETV) or tenofovir alafenamide (TAF) (if available) are recommended for people with established osteoporosis and/or impaired kidney function, and for children (ETV for those aged two years or older) or adolescents (TAF for those aged 12 years or older) as alternative regimen), for whom antiviral therapy is indicated