What is the hepatitis B jab?

The vaccine presents the immune system with a safe hepatitis B signal so it can respond more quickly to the real virus. It does not contain the whole infectious virus and cannot give you hepatitis B. Protection develops after the recommended doses, and the schedule can differ according to age, health, work exposure, travel, or a recent contact with the virus.

Common short-lived effects can include soreness where the injection was given, mild fever, or feeling tired. A vaccine does not treat an infection that is already present, so testing may still be needed after exposure.

Bring any vaccination records to your appointment and tell the clinician about pregnancy, immune problems, previous vaccine reactions, or a possible recent exposure. If you miss a scheduled dose, ask how to continue rather than restarting on your own. Household and sexual contacts of someone with hepatitis B may need testing and vaccination advice.

After a possible exposure, contact a clinic quickly. A clinician can decide whether vaccination, testing, or another preventive measure is appropriate. A liver function test may be used when illness is suspected, but it is not a substitute for vaccination.

Seek urgent care for breathing difficulty, facial swelling, fainting, or widespread hives after an injection. For a suspected hepatitis B exposure, seek prompt advice even if you feel normal. Dark urine, yellow eyes, severe vomiting, or unusual fatigue also warrant medical assessment.

Ask which schedule applies to you, when protection is expected, what to do if a dose is late, and whether testing is needed first. Check whether close contacts should be vaccinated and what symptoms should prompt a review.