Hepatitis B Vaccine (Energix)

Vaccination Services

Vaccination Services

Hepatitis B Vaccine (Energix)

Hepatitis B

Hepatitis B is an infection of the liver caused by Hepatitis B Virus (HBV) that's spread through blood and body fluids. Symptoms of hepatitis B can include: 

  • Tiredness / General aches
  • Fever
  • Feeling and being sick  
  • Yellowing of the skin and eyes (Jaundice)
  • Dark urine
  • Pale, grey-coloured 
  • stool

In Hong Kong, around 8% of the population are HBV carriers. It often doesn't cause any obvious symptoms in adults and typically passes in a few months without treatment. But in children, it often persists for years and may eventually cause serious liver damage.

Hepatitis B can be spread by:

  • A mother to their newborn baby
  • Injecting drugs and sharing needles
  • Having sex with an infected person without using a condom
  • Having a tattoo, body piercing, or medical or dental treatment in an unhygienic environment with unsterilised equipment
  • The blood of someone with hepatitis B getting into an open wound, cut, or scratch


Who should be vaccinated against hepatitis B?

  • All infants should be vaccinated to protect against hepatitis B infection.
  • This is because the infection can persist for many years in children and can eventually lead to complications, such as scarring of the liver or liver cancer.
  • People who change their sexual partners frequently
  • Close family or sexual partners of someone with hepatitis B
  • People with any form of chronic liver or kidney disease
  • People travelling to high-risk countries


What does hepatitis B immunisation involve?

Full protection involves having 3 injections of the hepatitis B vaccine (Engerix B) at the recommended intervals (over 6 months) and for most individuals it provides a lifelong protection against HBV. Hepatitis B vaccine is included in the Hong Kong Childhood Immunisation Programme since 1988. People who was born before or with incomplete immunisation is recommended to receive a booster dose.

The hepatitis B vaccine is very safe. Other than some redness and soreness at the site of the injection, side effects are rare. It's an inactivated (killed) vaccine, so it can't cause the infection itself.