What type of vaccine protects against hepatitis B?

It does not contain live hepatitis B virus, so it cannot give you hepatitis B. Instead, it presents a harmless part of the virus to the immune system. The body can then remember that target and respond more quickly if it encounters the virus later. Protection develops through a scheduled series, and the timing depends on age, health, occupation, and local vaccination guidance.

The vaccine prevents new infection; it does not treat an infection that is already present. Testing may be useful when exposure or symptoms raise concern. Hepatitis B can affect the liver, and symptoms may include fatigue or dark urine, although some people have no symptoms.

Ask a clinician whether vaccination is appropriate for you, especially if you have had blood or body-fluid exposure, work in healthcare, live with someone who has hepatitis B, or have a condition affecting the immune system. Bring your previous vaccine record if available. Tell the vaccinator about a serious reaction to an earlier dose, current illness, pregnancy, or medicines that affect immunity. Keep appointments in the recommended series and ask whether testing, such as a liver function test, is needed for your situation.

Contact a healthcare service promptly after a possible exposure because preventive treatment may be time-sensitive. Seek urgent help for severe breathing difficulty, facial swelling, fainting, or widespread hives after vaccination. Arrange medical assessment for yellowing of the skin, persistent vomiting, marked fatigue, abdominal pain, or dark urine. These symptoms do not identify the cause by themselves, but they warrant evaluation.

Ask which vaccine schedule fits your age and health, whether you need testing before or after vaccination, what to do if a dose is delayed, and whether household or workplace contacts should also be vaccinated.