What are hepatitis A and B?
Hepatitis A and B are both viral infections that cause inflammation in your liver. Hepatitis A is often a short-term illness, while hepatitis B can become chronic and lead to long-term complications such as increasing the risk of liver cirrhosis and liver cancer. Both viruses share similar symptoms, but they differ in how they are transmitted and the duration of infection.
What causes hepatitis A and B?
Hepatitis A and B are both caused by viruses that infect your liver and cause liver inflammation, but they have different causes.
Hepatitis A is caused by the hepatitis A virus (HAV). The primary cause of hepatitis A infection is ingesting food or water contaminated with the faeces of an infected person.
Common sources of contamination include drinking water from rivers or wells polluted with sewage, eating food that has been handled by someone who is infected and hasn't washed their hands, or consuming raw or undercooked shellfish from polluted waters.
Person-to-person transmission can also occur, especially in households or through certain sexual practices, such as oral-anal contact.
Hepatitis B is caused by the hepatitis B virus (HBV). The virus is transmitted through exposure to infected blood, semen, or other body fluids.
Common sources of HBV include unprotected sexual contact, sharing needles or other drug-injecting equipment, tattooing or piercing with unsterilised tools, sharing personal items like razors or toothbrushes, and from mother to baby during childbirth.
Hepatitis B is not spread through contaminated food or water nor through casual contact such as coughing or sneezing; it only occurs through contact with blood and other bodily fluids.
What are the symptoms for hepatitis A and B?
Hepatitis A and B share several common symptoms, including fatigue, abdominal pain, loss of appetite, nausea, and vomiting.
Some individuals may also experience fever, jaundice (yellowing of the skin and eyes), joint pain and dark urine. A severe symptom of both hepatitis A and B is acute liver failure.
Hepatitis A is a short-term infection that typically resolves on its own. Those infected with hepatitis A generally develop symptoms four weeks after exposure, and children under the age of 6 do not show symptoms. Moreover, once you have recovered from hepatitis A, you cannot be reinfected.
Hepatitis B, on the other hand, begins as a short-term infection but can become a chronic infection. This could potentially result in severe liver disorders like liver failure and a heightened risk of liver cancer. It's important to note that some people with hepatitis B may not experience any symptoms at all, especially young children.
If you have not been previously vaccinated for hepatitis or find yourself experiencing any of the above symptoms, please request an appointment with Thomson Medical today.
What is the importance of getting a hepatitis vaccination?
Vaccination against hepatitis A and hepatitis B is the most effective way to prevent both acute and chronic liver diseases within Singapore's population. Vaccinations help protect individuals from these viral infections and can effectively reduce the burden of liver-related illnesses and their potential complications.
Children are often more prone to infections due to their limited or developing immunity. Therefore, receiving vaccinations during childhood is crucial for early protection.
Who should get vaccinated for hepatitis?
Vaccination for hepatitis A and B is dependent on your age, lifestyle and health history.
Healthcare professionals are often recommended vaccinations for:
International travellers, particularly those who are visiting areas with high rates of hepatitis A.
Healthcare professionals due to potential exposure to infected blood and other body fluids.
Sewage service personnel due to exposure to poor sanitation.
People with chronic liver disease, as they are more susceptible to severe complications.
People who engage in high-risk behaviours, such as having multiple sexual partners or using intravenous drugs.
Individuals in close contact with people who have hepatitis B, such as those who are in a relationship with someone who has it.
People who are undergoing medical treatment, including dialysis and regular blood transfusions or blood products.
Children who are 1 year old and above.
All adults 18 years or older who have not been previously vaccinated.
The information provided is intended for general guidance only, but if you find yourself fulfilling any of the above criteria and want to receive your hepatitis vaccinations, please request an appointment with Thomson Medical today.
Who should not get vaccinated for hepatitis A and B?
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Individuals who should not receive a vaccination for hepatitis include:
Individuals who have experienced severe allergic reactions (anaphylaxis) from a previous dose or any component of the hepatitis A or B vaccine
Those with a history of bleeding disorders
Individuals who are currently sick
Breastfeeding or pregnant women
Children under the age of 1
Individuals with a weakened immune system due to conditions like HIV or cancer
Those currently taking any medications that may weaken your immune system
If you share any of these qualities, it is best to inform your doctor or a healthcare professional beforehand to discuss whether a hepatitis vaccine is suited for you or if there are any alternatives you can consider.
When should I get vaccinated?
The first dose of a hepatitis A vaccine is recommended at 12–23 months of age. Unvaccinated older children and adults can also receive the vaccine.
The first dose of a hepatitis B vaccine is given at birth. Unvaccinated adults can also start the series at any age. However, there may be some cases where you are no longer protected against hepatitis B during adulthood, despite receiving the vaccine at birth and needing to get vaccinated again.
How are the vaccines administered?
Both hepatitis A and B vaccines are given as injections into a muscle, usually the upper arm for adults and older children or the thigh for infants.
Children should receive the hepatitis A vaccine at one year old. When given on its own, two doses are usually required, one primary dose followed by a booster dose 6 to 18 months later.
When it comes to hepatitis B, the vaccine is typically administered in three doses. Children usually receive the first dose at birth, followed by the second dose at 1-2 months, and finally the third dose at 6-18 months. These vaccines are safe, highly effective, and provide long-term protection.
The hepatitis vaccine can be given on its own, as one shot, or in combination with other vaccines (e.g., hepatitis A and B).
What are the side effects of getting vaccinated for hepatitis?
Receiving a hepatitis vaccine can result in side effects afterwards. Common side effects of hepatitis A and B vaccines are usually mild and temporary, resolving within a day or two.
Side effects include:
Pain, redness, or swelling at the injection site
Headache
Fatigue
Fever
Loss of appetite
Nausea
Vomiting
Diarrhoea
These side effects can often be solved by taking a paracetamol for pain relief, headaches or fevers. If any side effects last more than a few days or worsen, consult a healthcare professional.
How much is the hepatitis A and B vaccine in Singapore?
The hepatitis B vaccine is covered under the vaccination and childhood development screening subsidies (VCDSS). Hence, at polyclinics and selected MOH-funded long-term care institutions, Singaporean citizens (SC) and permanent residents may receive subsidies for nationally recommended vaccinations.
The prices of the hepatitis B vaccine are as follows:
Eligible SCs children: SGD 0
Eligible Pioneer Generation (PG) cardholders: capped at SGD 9 to SGD 16 per vaccination dose
Eligible Merdeka Generation (MG), CHAS Blue and Orange cardholders: capped at SGD 18 to SGD 31 per vaccination dose
Other eligible adult SCs: capped at SGD 35 to SGD 63 per vaccination dose
At private clinics, the cost of a hepatitis A and B vaccine ranges from SGD 55 to SGD 130 per dose depending on whether you get an individual or combination vaccine. These prices vary between clinics and do not include consultation fees or additional tests.
This article was written in May 2025. As such, the prices reflected for MOH’s VCDSS may have changed since then. Please visit the MOH website for the most accurate pricing.
FAQ
Do you need both the hepatitis A and B vaccines?
Yes, because hepatitis A and B are caused by different viruses. If you need protection against both, you can choose a combined vaccine.
How many years does the hepatitis A and B vaccine last?
The hepatitis A vaccine usually provides protection for at least 20 years and potentially for life. The hepatitis B vaccine usually provides immunity for 20 to 30 years, with many people remaining protected for life. For most people, booster doses aren't necessary after completing the full course of vaccinations.
How many times do you need to get the hepatitis B vaccine?
You will usually need three doses over a period of six months. However, if you are travelling or have specific requirements, you may be offered an accelerated schedule.
Which is more important: hepatitis A or B vaccine?
Both vaccines are important, but hepatitis B is generally considered more critical due to its potential to cause chronic infection, which can lead to severe liver complications such as cirrhosis and liver cancer. While hepatitis A is serious, it usually resolves on its own and does not lead to chronic disease. This is why it is especially important to get vaccinated against hepatitis B if you are part of a high-risk group or are at potential risk of exposure to the virus.
At what age is the hepatitis A vaccine given?
The first dose is recommended at 12–23 months of age. However, if you are older and at risk, you can still be vaccinated.
Can you get a combined hepatitis A and B vaccine?
Yes, the combined vaccine (such as Twinrix) protects you against both hepatitis A and B and is administered in three doses over six months.
What are the disadvantages of combination vaccines?
You might experience mild side effects like soreness at the injection site, and the cost per dose may be higher. But these side effects are generally temporary.
What are the advantages of combination vaccines?
Combination vaccines offer the convenience of fewer injections, improved compliance, and protects you against both hepatitis A and B with a single vaccination schedule.
The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Request an appointment with Thomson Medical today.
For more information, contact us:
Thomson 24-Hour Urgent Care Centre (Novena)
- Call: 6350 8812