Hepatitis B is a serious disease caused by a virus that attacks the liver. The virus, which is called hepatitis B virus (HBV), can cause lifelong infection, cirrhosis (scarring) of the liver, liver cancer, liver failure, and death
If hepatitis B vaccine is administered before infection, it prevents the disease and the carrier state in almost all individuals.
The hepatitis B vaccine can provide protection in 90% to 95% of healthy young adults. The vaccine can be given safely to infants, children, and adults, usually in three doses over a 6-month period. Even pregnant women can be safely given these shots, if their risk factors warrant it. Hepatitis B shots are very safe, and side effects are rare. Hepatitis B vaccine is that first vaccine that prevents cancer—liver cancer.