What should you know about the hepatitis A and B vaccine?

Hepatitis A and hepatitis B are caused by different viruses and spread in different ways. A combined vaccine may be suitable when both forms of protection are needed, while some people may be offered a vaccine for only one virus. The choice depends on previous doses, travel plans, work or household exposure, medical history, and local vaccination guidance. Vaccination cannot clear an infection that has already started.

The immune response develops after vaccination, so protection may not be immediate. A clinician will explain the recommended schedule and whether further doses are needed. Keep your record so future providers can distinguish completed vaccination from an uncertain history.

Tell the vaccinator about allergies, a previous vaccine reaction, pregnancy, immune conditions, and medicines. Ask about the timing of later doses and what happens if one is late. Injection-site tenderness, mild fever, headache, or tiredness can happen for a short time. Rest and drink fluids, and use symptom relief only if it is appropriate for you. Continue sensible food, hand, and sexual-health precautions because vaccination does not cover every cause of hepatitis or replace exposure advice.

Get emergency help for breathing difficulty, facial or throat swelling, widespread hives, fainting, or severe dizziness soon after an injection. Contact a clinician if a reaction is worsening or you feel seriously unwell. After a possible exposure, seek advice promptly even if you feel well. New nausea, dark urine, loss of appetite, or a generally unwell feeling should be assessed rather than attributed automatically to a vaccine or to hepatitis.

Ask whether you need combined or single-virus vaccination, which doses are due, how previous records change the plan, and what precautions apply after travel or a known exposure.