Formation and transcriptional regulation of hepatitis B virus covalently closed circular DNA

Hepatitis B virus (HBV) is a hepatotropic viral pathogen of the Hepadnaviridae family, causing at least 296 million chronic infections worldwide. Despite the existence of a prophylactic vaccine, current treatments are not curative as they fail to completely eliminate covalently closed circular DNA (cccDNA) – the major template for viral gene transcription - from the nucleus of infected hepatocytes.