Hepatitis B

The hepatitis B vaccine helps prevent infection with the hepatitis B virus. It stimulates the body to produce protective antibodies against the virus. It cannot treat an existing hepatitis B infection.

Children receive hepatitis B vaccination under Hong Kong's childhood immunisation programme. Adults who have neither hepatitis B infection nor protective antibodies may need vaccination, following clinical assessment.

DH recommends vaccination for people at higher risk of infection. Examples include family members and sexual partners of people with chronic hepatitis B, healthcare workers who may be exposed to blood or body fluids at work, and people on dialysis.

Start with the records you have

A documented vaccination history helps your clinician assess what you have received and whether any doses are missing. Not finding a record does not establish that you were never vaccinated.

Hong Kong introduced universal childhood hepatitis B vaccination in 1988. That programme history does not prove an individual’s doses, protection or infection status. This also applies if you recall being vaccinated as a child.

For records from public services, use the Family Health Service record-application page to find the form for the service where vaccination took place. DH2797 covers clients who received childhood immunisation through MCHCs, Student Health Service Centres or School Immunisation Teams. FHS124 and FHS139 serve different, specified groups. For other records, ask the service that administered the vaccination what records it holds.

Understand what testing is for

Adults can have blood tests before vaccination to check their hepatitis B status and help determine whether vaccination is needed. Discuss which tests are appropriate with your clinician.

Hepatitis B surface antigen (HBsAg) is used to assess infection. Hepatitis B surface antibody (anti-HBs) is used to assess immune status. These are general purposes, not instructions for interpreting your own report. Bring previous reports for professional review.

Testing before vaccination and testing the response after vaccination are separate questions. Do not decide that a later low antibody result automatically means you need a booster. Your clinician should consider the timing, documented course and circumstances, including occupational exposure or health conditions.

If you already have hepatitis B

Hepatitis B vaccination prevents infection; it does not treat an established infection. Seek medical assessment and follow-up rather than expecting a vaccination course to manage it.

A clinician assesses whether treatment or investigations are needed. A family member or sexual partner of someone with hepatitis B can also discuss testing and prevention with a clinician. Avoid assuming that all family members have the same infection or vaccination status.

The standard hepatitis B vaccination course described by DH has three doses at 0, 1 and 6 months. Under the Hong Kong Childhood Immunisation Programme, the infant doses are given at birth, one month and six months.

If a hepatitis B course is interrupted, DH says the series does not need to restart. Bring your dose dates and ask a healthcare professional to arrange the remaining doses. Do not use this standard example to select a special or accelerated regimen.

Babies born to mothers with hepatitis B have a separate prevention and follow-up pathway, including additional measures around birth and post-vaccination serologic testing. Follow the maternity and child-health team’s plan; an adult pre-vaccination-testing discussion should not delay newborn care.

Drug Office records checked on 13 October 2026 identify the following Engerix-B presentations. Registration identity does not establish the product suitable for you, clinic stock or a particular dosing schedule. Confirm the exact product and its Hong Kong approved information with the clinician.

These product names are reference examples, not a complete list of registered products or confirmation of current supply. Confirm the exact product and availability with the provider.

Possible reactions include soreness at the injection site, which usually settles within one or two days. CHP also describes injection-site pain or swelling and tiredness in some children.

Severe allergic reactions are rare. Tell the clinician about any reaction to a previous dose or known allergy to a vaccine component before vaccination. The clinician should assess whether the exact product is suitable for you.

Adults can ask a family doctor or a private vaccination clinic about hepatitis B vaccination. Some private service options are listed below.

For children, the birth dose is given in hospital. DH Maternal and Child Health Centres provide hepatitis B vaccination for children from birth to five years old. School Immunisation Teams provide catch-up vaccination for primary school children who have not completed the course; confirm the service arrangements with the relevant team.

Before booking, confirm the exact product, availability, testing requirements and price with the provider. Check how many doses an offer includes: a one-dose price is not a complete-course price.

Print the hepatitis B appointment worksheet

• DH — Hepatitis B vaccination / 乙型肝炎疫苗 · Department of Health, Hong Kong (HK)Source checked: 2026-10-16
• DH — Testing / 檢測肝炎 · Department of Health, Hong Kong (HK)Source checked: 2026-10-16
• DH — Hepatitis B Q&A / 乙型肝炎問與答 · Department of Health, Hong Kong (HK)Source checked: 2026-10-13
• FHS — Record applications / 紀錄申請 · Department of Health, Hong Kong (HK)Source checked: 2026-10-16
• CHP — Hepatitis B vaccine / 乙型肝炎疫苗 · Department of Health, Hong Kong (HK)Source checked: 2026-10-13
• Drug Office — Engerix-B10 HK-65375 · Department of Health, Hong Kong (HK)Source checked: 2026-10-13
• Drug Office — Engerix-B20 HK-65374 · Department of Health, Hong Kong (HK)Source checked: 2026-10-16
• DH — Mother-to-child prevention / 預防母嬰傳播 · Department of Health, Hong Kong (HK)Source checked: 2026-10-13
• DH — Focused risk-based testing (June 2022) · Department of Health, Hong Kong (HK)Source checked: 2026-10-13