Hepatitis B is a viral infection that affects the liver. It is caused by the hepatitis B virus (HBV) and can be transmitted through bodily fluids such as blood, semen, or vaginal secretions. The virus can be spread through:

• Sexual contact with an infected person
• Sharing needles or syringes with an infected person
• Accidental needle sticks
• Mother-to-child transmission during childbirth
• Sharing of personal items such as toothbrushes or razors with an infected person

Most people with hepatitis B have no symptoms, but for those who do, symptoms can include fatigue, poor appetite, stomach pain, nausea, and jaundice. For many people, hepatitis B is a short-term illness, but for others, it can become a long-term, chronic infection that can lead to serious, even life-threatening health issues like liver disease or liver cancer. Age plays a role in whether hepatitis B will become chronic. The younger a person is when infected with the hepatitis B virus, the greater the chance of developing chronic infection.

Hepatitis B can be prevented with a safe and effective vaccine, which is usually given soon after birth with boosters a few weeks later. The vaccine offers nearly 100% protection against the virus. If a person thinks they have been exposed to the virus, they should see their healthcare provider or local health department immediately and ask if the hepatitis B vaccine and/or a shot called “HBIG” (hepatitis B immune globulin) is right for them. These measures can prevent infection if a person gets treatment as soon as possible, ideally within 24 hours after exposure.