Adaptability of an Undetectable = Untransmissible Model for HBV

Inclusion Criteria: Infected Individuals * Individuals above 18 years and less than 65 years with chronic hepatitis B infection * Included according to undermentioned three arms: * Infected, On-treatment arm: subjects being treated with TAF/TDF for a minimum of 2 years with sustained viral suppression indicating adherence to therapy * Infected, Untreated control arm: Immune tolerant subjects; 15 with high viral load (\>10\^6) and 5 with low viral load (\<10\^6) * Uninfected Assay Validation controls: 10 subjects with history of prior infection who have convalesced i.e., have lost surface antigen, and developed surface antibody with viral eradication * Able and willing to provide informed consent Healthy Controls * Individuals above 18 years and less than 65 years who have never been infected and have been vaccinated * Able and willing to provide informed consent Exclusion Criteria: * Individuals less than 18 years or greater than 65 years of age * Prior surgery to genitourinary tract, including prior vasectomy * Prior interferon therapy * HIV co-infection * Hepatitis C virus co-infection * Hepatitis delta virus co-infection