What should you know about BCG and hepatitis B?

BCG is a live attenuated vaccine associated with protection against serious forms of tuberculosis. Hepatitis B is a viral infection that can affect the liver, and its vaccine prepares the immune system to respond to that virus. Having BCG does not replace hepatitis B vaccination, and hepatitis B vaccination does not replace BCG.

Hepatitis B can be present without obvious symptoms. When symptoms occur, they may include fatigue or dark urine, but these signs have many possible causes. A clinician may use a liver function test alongside specific hepatitis testing when assessing liver health.

Check your immunisation record and tell the healthcare professional about previous doses, allergies, pregnancy, immune conditions, and medicines. The recommended timing depends on age, country guidance, exposure risk, and health history. If you are unsure whether a dose was given, ask the clinic to review available records before making a plan. Vaccination is preventive; it is not a treatment for established hepatitis B.

Get urgent help for breathing difficulty, swelling of the throat or face, collapse, or a rapidly spreading rash after vaccination. Seek prompt medical advice for yellow skin or eyes, dark urine, severe tiredness, persistent vomiting, or significant abdominal pain. These symptoms warrant assessment because liver and other conditions can present similarly; they do not by themselves establish hepatitis B.

Ask which vaccine is relevant to your situation, whether your records show completed doses, whether hepatitis testing is appropriate, and how to interpret any liver function results.