Hepatitis B virus
The Hepatitis B virus (HBV) is a DNA virus of the Hepadnavirus family. Approximately 350 million people worldwide (including 1.2 million in the U.S.) are infected, with about 1 million people per year dying of HBV-related liver disease. It is a major cause of hepatocellular carcinoma (liver cancer) and cirrhosis. A safe and effective vaccine is widely available to prevent HBV infection.