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