Hepatitis B virus is a DNA virus that belongs to the hepatophilic DNA virus family (hepadnavividae). As far as is known, HBV is susceptible only to humans and orangutans and causes viral hepatitis B disease. The intact hepatitis B virus is in the form of particles, which are also known as Dane particles. Hepatitis B virus was discovered by Dane in 1965. The diameter is 42 nanometers and the particles are divided into two parts: the outer shell and the core. Viral Mechanism After the virus enters the hepatocyte, the capsid is shed and the DNA enters the nucleus of the hepatocyte. Positive-stranded DNA is prolonged and patched into a complete state by the action of DNA polymutase, using the negative strand as a template. The double-stranded DNA forms a closed-loop superhelix. Catalyzed by cellular RNA polymutase, the negative-stranded DNA is transcribed into RNAs of varying lengths. the shorter RNAs serve only as messenger RNAs, while the longer ones are still pregenomic RNAs. from the messenger RNAs, e antigens, core antigens, DNA polymutase, and three surface antigens are translated. The core antigens are assembled into an underwear shell. The pregenomic and DNA polymorphic enzymes enter the assembled viral underwear shell. In the presence of DNA polymutase (reverse transcriptase), the pregenomic RNA is reverse transcribed to negative-stranded DNA, and the pregenome is degraded and lost. The underwear shell containing the double-stranded DNA is wrapped in an outer shell and becomes the virion. It is released from the hepatoplasm to the outside of the hepatocyte.