What should you know about hepatitis B virus vaccine?

Vaccination helps the immune system recognise hepatitis B before the virus can establish infection. It does not treat an existing hepatitis B infection, and it does not replace testing after a possible exposure. A clinician can recommend a schedule based on age, health, previous doses, work or travel risks, and whether protection is needed quickly. People who have already had hepatitis B may still need medical advice about vaccination and testing.

Bring any previous vaccine record to your appointment and tell the clinician about pregnancy, immune-system problems, serious allergies, or a prior reaction to a vaccine. Ask whether partners and household members should be vaccinated. If you have had a recent blood or sexual exposure, seek advice promptly rather than waiting for routine vaccination. A [Liver Function Test](/treatments/diagnostics-and-screening/liver-function-test/) checks liver health; it does not show whether the vaccine has worked. Learn more about [Hepatitis B](/conditions/hepatitis-b/).

Get urgent help for trouble breathing, facial swelling, collapse, or widespread hives after vaccination. Contact the vaccination clinic for persistent fever, worsening illness, or concern about a reaction. Seek medical advice after a possible exposure even if you have been vaccinated, because the right response depends on your documented doses and the exposure.

Ask which schedule applies to you, whether you need testing, how to handle a missed dose, and whether a blood test is needed after vaccination. Mention symptoms such as [Dark Urine](/symptoms/dark-urine/) or [Fatigue](/symptoms/fatigue/) so they can be assessed rather than attributed to the vaccine.