HBV

Hepatitis B virus (HBV) is the smallest hepadnavirus of about 42 nm in diameter, which has a partially double-stranded circular DNA genome of 3.2 kb. The viral genome together with the viral polymerase are packed inside the nucleocapsid core (HBeAg), surrounded by an outer lipoprotein coat (envelope) containing the surface antigen (HBsAg). Compared to other human viruses, HBV is unusual in that it contained a vast excess of noninfectious subviral particles composed only of viral surface proteins and lipids, appear predominantly as 22 nm spheres and filaments with a diameter of 22 nm.