Hepatitis B Vaccine

(Content revised 10/2022)

Hepatitis B

Hepatitis B is a type of infection of the liver caused by hepatitis B virus.  It is transmitted by blood and body fluids.  A mother who is a hepatitis B carrier has a great chance of transmitting the virus to her baby at or around the time of delivery.

Symptoms of acute hepatitis include extreme tiredness, loss of appetite, vomiting, diarrhoea and yellow discoloration of the skin and whites of the eyes.  Majority of acute infections resolve completely.  However, some people may become chronic carriers, who may eventually develop chronic liver diseases, such as cirrhosis of the liver and liver cancer.

Hepatitis B Vaccine (HBV)

A. Why get vaccinated?

Hepatitis B vaccine (HBV) can effectively protect against hepatitis B and its complications like liver cancer.  In Hong Kong, HBV is included in the Hong Kong Childhood Immunisation Programme.

B. When should my child get vaccinated?

  1. Full Term Babies

    The standard vaccination scheme is as follows:

    Babies born to hepatitis B carrier mothers Babies born to non-hepatitis B carrier mothers
    Birth Dose / First Dose Within 24 hours after birth
    (together with hepatitis B immunoglobulin)    		 Within 24 hours after birth
    Second Dose 1 month of age
    Third Dose 6 months of age

    To achieve the best and lasting protection, children must complete all three doses of HBV.  HBV can be given together with other types of vaccines.

  2. Preterm Babies

    All preterm babies born to hepatitis B carrier mothers should receive HBV together with hepatitis B immunoglobulin at birth.  However, this dose may not be counted in the 3-dose course of vaccination.  If the attending paediatrician considered this dose as invalid, the first valid dose should be given to the baby 4 weeks later.

    All preterm babies born to non-hepatitis B carrier mothers with birth weight 2kg or more should receive the first dose of HBV at birth.  Preterm babies with birth weight less than 2kg should receive the first dose of HBV by the time the baby's body weight achieves 2kg or the baby is at one month of age, whichever is earlier.

  3. Other Situation

    Children who have not yet received or not yet completed a full course of hepatitis B vaccination should receive or complete hepatitis B vaccination to protect their health.

C. The following individuals should NOT receive HBV

  • serious allergic reaction to yeast (for baking bread)
  • serious allergic reaction to previous dose of HBV

D. What are the side effects?

  • HBV is a mild vaccine and normally does not cause serious adverse reactions.
  • Occasionally there may be slight soreness around the injection site, but these will gradually subside in 1-2 days.

If you have any query, please contact Maternal & Child Health Centres of the Department of Health.

Post-vaccination serologic testing (PVST)

  • After a 3-dose course of hepatitis B vaccination, babies born to mother infected with hepatitis B virus should receive PVST to assess their immune response to vaccination and hepatitis B infection status.
  • Please refer to the factsheet on “PVST” for more information.