What is Hepatitis A?

Hepatitis A is associated with water contamination. It is caused by hepatitis A virus and one type of infection affecting the liver. Its incubation period is 15-50 days (28-30 days in average). The onset includes fever, fatigue, upper abdominal pain, loss of appetite, nausea, and jaundice. Hepatitis A will not lead to chronic liver disease or death, but acute liver failure may occur to some patients. Most of the patients will recover from the disease and get lifelong immunity.


Transmission of Hepatitis A

Hepatitis A virus can survive for 12 months in water and a few days in food. The virus is transmittable through human when someone is infected by eating and drinking contaminated food and water, e.g. oysters and mussels that are not cooked properly. The virus thrives in places where sanitary conditions are poor. If hands make contact with the virus, it can also be transmitted.


Prevention of Hepatitis A

Hepatitis A is intermediately prevalent in Hong Kong. However, infection could be prevented through vaccination. The vaccine is applicable to people aged 2 years or above. Two doses are needed in order to develop immunity against the virus. The first injection and the second one should be given 6-18 months apart. After the first injection, immunity will develop in 4 weeks to fight against the virus. The second injection is a booster that can ensure immunity over 10 years or more.

Maintain personal hygiene and food clean will also prevent Hepatitis A infection:

  • Flush the toilet and clean your hands with soap
  • Avoid eating and drinking unclean food and beverage
  • Avoid adding unclean ice
  • Avoid eating uncooked food (especially shellfish)
  • Avoid eating fruits that are cut or peeled


Who should be vaccinated?

  • Frequent visit to or residing in middle to high risk places, e.g. Mexico, Caribbean, and Africa
  • Male homosexuals and bisexuals
  • Food and catering operators
  • Patients suffering from chronic liver disease
  • People diagnosed with immunosuppression
  • People having intimate contact with the infected


What are the common side effects?

The only common side effect is the pain caused by the injection, but it will wear off soon. Some people will have redness, swelling, and discomfort, for example, fatigue, headache, fever, and loss of appetite. The conditions will resolve in 24 hours.


Who are not recommended to get vaccinated?

  • People who are allergic to vaccines
  • People who are having severe fever


Important Notes

  1. Must have checked Hepatitis A/B antigen and antibody within 3 months and provide a valid test report for the doctor to determine whether you are suitable for the injection.
  2. For those who fail to provide a valid report, Hepatitis A/B antigen and antibody test can be completed at our center (additional test fee required).

Our registered doctor will provide consultation to determine whether you are suitable for the injection (consultation fee is HK$380).



  1. Viral Hepatitis Preventive Service, Department of Health
  2. Travel Health Service, Department of Health
  3. Travel Health Service – Hepatitis A Vaccination 
  4. Canadian Liver Foundation
  5. Centers for Disease Control and Prevention