Hepatitis B second dose: what to know

Hepatitis B vaccination is given as a series because the immune response is built over separate doses. The second dose is not a test for hepatitis B and cannot treat an existing infection. A delayed appointment does not mean you should restart the course automatically; the vaccinating clinician can check your record and plan the next dose.

A sore arm, mild fever, tiredness, or feeling unwell can occur after vaccination. These effects usually settle, but tell the clinician about previous reactions, pregnancy, immune conditions, or a serious allergy before another dose.

Bring your vaccination record and mention any doses received at another clinic. If you are unwell, ask whether the appointment should go ahead. After vaccination, follow the clinician's observation advice and keep the next appointment visible in your calendar. Vaccination does not remove the need for safer sex or blood-exposure precautions.

Seek urgent help for trouble breathing, swelling of the face or throat, widespread hives, collapse, or rapidly worsening symptoms after vaccination. Contact a clinician for a persistent high fever, severe weakness, or a reaction that concerns you. If you have fatigue or dark urine before the appointment, ask for medical assessment rather than assuming it is a vaccine effect.

When should my next dose be given? What should I do if this dose was late? Do I need any blood testing because of my work or an exposure? Would a Liver Function Test be relevant to my symptoms?