What should you know about hepatitis B after vaccination?

The vaccine trains your immune system to recognise hepatitis B surface proteins. It does not contain live hepatitis B virus, so it cannot cause the infection. Protection builds after vaccination rather than appearing instantly, and the recommended course may involve more than one dose. Keep the next appointment even if the injection site feels normal.

A tender, red, or swollen injection site, tiredness, headache, or a mild temperature can occur for a short time. These reactions usually settle without treatment. They are different from hepatitis B symptoms, which can include marked fatigue, nausea, abdominal discomfort, yellowing of the skin or eyes, and dark urine. Read more about [Hepatitis B](/conditions/hepatitis-b/).

Rest if you feel unwell, drink fluids, and use a cool cloth over a sore injection site. Follow the aftercare advice from the vaccinating clinician before taking any medicine for discomfort, particularly if you have liver disease, are pregnant, or take regular medicines.

Record the date and product if it was provided to you, and check when the next dose is due. If you were vaccinated because of a recent exposure, vaccination may be only one part of the response; contact a clinician promptly so they can assess the exposure and decide whether additional care or testing is needed. Details about the vaccination course are available under [Hepatitis B Vaccination](/treatments/preventive-care-and-vaccination/hepatitis-b-vaccination/).

Seek emergency help for trouble breathing, swelling of the face or throat, widespread hives, fainting, or sudden severe weakness after vaccination. These may signal a serious allergic reaction.

Arrange prompt medical advice for persistent vomiting, severe abdominal pain, yellow skin or eyes, unusually dark urine, confusion, or worsening illness. A clinician may review your symptoms, vaccination record, and exposure history and may order a [Liver Function Test](/treatments/diagnostics-and-screening/liver-function-test/). Fatigue alone has many possible causes; information about [Fatigue](/symptoms/fatigue/) can help you describe its pattern.

Ask which dose you received, when the next dose is due, whether your medical conditions or medicines alter the plan, and whether testing is appropriate for your work, health history, or a recent exposure. Also ask which symptoms should trigger same-day advice.