Hepatitis B Vaccine Hong Kong: Common Questions & Answers

Hepatitis B is an infection of the liver that stems from the hepatitis B virus (HBV). The best way to prevent hepatitis B is by getting vaccinated with the hepatitis B vaccine. In this blog, we have summarised the important and frequently asked questions regarding the hepatitis B vaccine.

Hepatitis B Vaccination in Hong Kong

In Hong Kong, the hepatitis B vaccination has been part of the Childhood Immunisation Programme since 1988 and is highly effective in preventing HBV infection.

All babies are administered the same 3-dose vaccination program with half the adult dose.¹

Frequently Asked Questions Regarding Hepatitis B (HBV) and the Hepatitis Vaccine

What are the Common Symptoms of HBV?

In adults, hepatitis B usually shows no obvious symptoms and can pass without treatment. However, it can persist for longer for children and, if left untreated, will affect the liver.

Approximately 5-10% of adults and 95% of potentially infected infants cannot clear the virus themselves and become chronic carriers.²

Symptoms of hepatitis B usually occur within three months of exposure. The following are common symptoms:³

• Fever
• Change of colour of urine to a darker tint
• Abdominal pain
• Yellow tint to skin and eyes (jaundice)
• Nausea/vomiting
• Loss of appetite
• Fatigue

How is HBV transmitted?

The hepatitis B virus is found in an infected person's blood or bodily fluids. It's most commonly transmitted through the following ways:

• Sexual exposure: Hepatitis B is transmitted through contact with infected semen, saliva and other bodily fluids. 
• Through blood contact: Direct contact with infected blood and sharing contaminated needles. 
• Childbirth: Pregnant women infected with HBV can transmit the virus to their newborns.

HBV and Pregnancy

As the symptoms of infection in most cases are mild, pregnant women who are HBV carriers may be unaware that they carry the virus and can unknowingly pass it to their infants.

Therefore, pregnant women must know their hepatitis B status. All pregnant women should be screened for HBV during their pregnancy. Learn more about antenatal screening during pregnancy.

Who can get hepatitis B vaccine?

The Hepatitis B vaccine is accessible to individuals across all age brackets. It's advised that this group of people should receive the vaccine: 

• All infants and children or adolescents under 19 who have yet to be vaccinated.
• Adults ranging from 19 to 59 years old 
• 60 years or older who are at risk for a Hepatitis B infection. Even adults aged 60 or more without identifiable risk factors for Hepatitis B can opt for the vaccine.

Who should be vaccinated against HBV?

The following high-risk groups should also receive the vaccine:

• Those who have been in close contact with an individual infected with the hepatitis B virus.
• Those who are regular intravenous drug users and often share needles
• Healthcare professionals who have been in contact with HBV-infected patients.
• Those who regularly go through dialysis treatment or other forms of blood transfusions.
• Those who have had sexual contact with an HBV-infected individual.

Who should not receive the HBV vaccine?

The hepatitis B vaccine has proven to be very safe, effective, and highly recommended for most individuals. However, if you have a history of allergic reactions to vaccine ingredients, please seek medical advice before taking the hepatitis B vaccine.

How long does protection from the HBV vaccine last, and is a booster dose necessary?

Protection from the vaccine lasts up to 20 years and most probably extends for the entire period of an individual's life.⁵ For this reason, a booster dose is not recommended.

A blood test can be taken to determine whether a booster dose will be necessary.

What is the recommended HBV regimen in Hong Kong?

In Hong Kong and most other international communities, the recommended hepatitis B regimen is a 3-dose vaccine administered:¹

• Dose 1: Birth
• Dose 2: 1 month of age
• Dose 3: 6 months of age

What is the difference between Acute Hepatitis and Chronic Hepatitis?

An HBV infection can be an acute infection or a chronic infection. An acute infection is when infection may last up to six months. Most healthy individuals don't show symptoms and can pass the virus without any problems. Individuals who cannot get rid of the virus after six months are diagnosed with a chronic infection.⁶

A blood test can diagnose an acute or chronic hepatitis B infection.

How can HBV be treated?

There is no specific treatment for acute hepatitis B other than treating the symptoms.

Chronic hepatitis B is treated with medication, including oral antiviral agents.⁵

Antiviral drugs don't cure hepatitis B infection but suppress the replication of the virus to reduce virus-induced liver damage⁴. For this reason, people who start hepatitis B treatment continue taking it for life.

What can I do to protect myself from getting infected?

The best possible way to prevent a hepatitis B infection is to get vaccinated.

Since hepatitis B spreads through contact with blood or bodily fluids, there are also other precautions you can take to protect yourself:²

• Wash your hands thoroughly and regularly with soap after coming into contact with blood and other bodily fluids.
• Avoid having unprotected sexual contact.
• When getting a tattoo or body piercing, ensure that the environment is hygienic and needles are sterile.
• Avoid sharing needles.

The hepatitis B vaccine is the most effective and safe way to prevent HBV infection and liver diseases caused by HBV infection. We recommend everyone consult their family doctor for advice and arrangements for the hepatitis B vaccination. 

To read more about what vaccinations all adults in Hong Kong should receive, click here. We have also developed a Hong Kong vaccination calculator to guide you through all the vaccinations you should consider.

References

1. Family Health Service. (2020). ‘Schedule of Hong Kong Childhood Immunisation Programme’. Department of Health. May 2020. Available at: <https://www.fhs.gov.hk/english/main_ser/child_health/child_health_recommend.html> [Accessed 19 July 2021]

2. Centre for Health Protection. (2019). ‘Hepatitis B’. Department of Health. 10 April 2019. Available at: <https://www.chp.gov.hk/en/healthtopics/content/24/27.html> [Accessed 19 July 2021]

3. National Health Service. (2019). ‘Hepatitis B’. NHS. 30 January 2019. Available at: <https://www.nhs.uk/conditions/hepatitis-b/> [Accessed 19 July 2021]

4. Viral Hepatitis Control Office. (2020). ‘Hepatitis B’. Department of Health. 26 February 2020. Available at: <https://www.hepatitis.gov.hk/english/what_is_hepatitis/hepatitis_b_04.html> [Accessed 19 July 2021]

5. World Health Organisation. (2020). ‘Hepatitis B’. WHO. 27 July 2020. Available at: <https://www.who.int/news-room/fact-sheets/detail/hepatitis-b> [Accessed 19 July 2021]

6. Hepatitis B Foundation. (2021). ‘Acute vs. Chronic Hepatitis B’. Available at: <hepb.org/what-is-hepatitis-b/what-is-hepb/acute-vs-chronic/> [Accessed 19 July 2021]