Hepatitis B is a disease caused by the hepatitis B virus (HBV). This virus attacks the liver. The disease can cause:

HBV is spread through the blood or other body fluids of an infected person.

Most hepatitis B infections clear up without treatment. Others develop into chronic hepatitis B. This can lead to serious complications, even death.

The hepatitis B vaccine is produced by inserting a gene for HBV into yeast. The yeast is grown, harvested, and purified. The vaccine is given as an injection into the muscle. This is usually given in a series of 3-4 shots during a 6-month period.