Hepatitis A & B Vaccines – Prevent Liver Cancer and Chronic Hepatitis
Hepatitis is one of the leading causes of chronic liver disease and liver cancer in Thailand — particularly hepatitis A and B, which can be easily transmitted through contaminated food, blood, or bodily fluids. Vaccination remains the most effective and safest way to prevent these infections.
The hepatitis A–B vaccine helps the body build immunity against both viruses, reducing the risk of chronic hepatitis, liver cirrhosis, and liver cancer. The World Health Organization (WHO) and Thailand’s Ministry of Public Health recommend this vaccine as part of routine immunization, especially for high-risk individuals or those who have never been vaccinated.
Safe Clinic provides professional hepatitis vaccination services under the supervision of experienced doctors — from pre-vaccination consultation to follow-up care — ensuring safety and long-term protection for every patient.
What Are Hepatitis A and B Vaccines?
The hepatitis A and B vaccines help the body develop immunity against two major viruses that cause liver inflammation — hepatitis A and hepatitis B — both of which can lead to acute or chronic liver disease.
These viruses can spread through contaminated food, blood, or bodily fluids, and may cause long-term complications such as liver cirrhosis or liver failure. Vaccination is the most effective and safest way to prevent infection by stimulating the body’s immune system before exposure.
The World Health Organization (WHO) and Thailand’s Ministry of Public Health recommend hepatitis A and B vaccination for both children and adults, particularly those at higher risk, such as healthcare workers, individuals exposed to blood, or travelers to endemic regions.
The Difference Between Hepatitis A and B
Although hepatitis A and hepatitis B share similar names, they differ in how they spread, their severity, and their long-term effects.
Hepatitis A spreads mainly through contaminated food or water. It usually causes acute symptoms such as fever, fatigue, and nausea, but most people recover completely within weeks without developing chronic liver disease.
Hepatitis B, on the other hand, spreads through blood, semen, and other bodily fluids — for example, through unprotected sex, sharing needles, or from mother to child during birth. It is more serious because it can lead to chronic hepatitis, liver cirrhosis, or liver cancer over time.
Vaccination against both hepatitis A and B is the most effective prevention, especially for high-risk groups who should complete the recommended vaccination schedule under medical supervision.
How Does Hepatitis Spread?
Hepatitis viruses spread through different routes depending on the type. Hepatitis A (HAV) is commonly transmitted via the fecal–oral route, often through contaminated food or water — such as raw seafood, ice, or food that hasn’t been properly cooked.
Hepatitis B (HBV), however, spreads through contact with infected blood or bodily fluids. This includes sharing needles, tattoos or piercings done with unsterilized equipment, unprotected sexual contact, or transmission from mother to child during birth.
Simple hygiene practices — washing hands before eating, consuming well-cooked food, and getting vaccinated against hepatitis A and B — are effective ways to prevent infection
Who Should Get the Hepatitis Vaccine?
While hepatitis vaccines are recommended for everyone, certain groups are at higher risk and should be prioritized — such as healthcare workers, laboratory staff, and anyone exposed to blood or sharp instruments that could carry infection.
Travelers to regions where hepatitis A or B is common, individuals who engage in unprotected sex, and people who share needles are also strongly advised to get vaccinated to reduce the risk of infection.
Young children, the elderly, and those with chronic liver disease should consult their doctors about vaccination, especially if they have never received the vaccine or are unsure of their immunity status.
What Diseases Do Hepatitis A and B Vaccines Prevent?
Hepatitis A and B vaccines protect against two major types of viral hepatitis that directly affect liver function and overall long-term health.
The hepatitis A vaccine prevents acute liver inflammation caused by food or water contaminated with the virus. It helps protect against symptoms like jaundice, fatigue, and in rare cases, acute liver failure.
The hepatitis B vaccine protects against infection spread through contact with infected blood or bodily fluids — a major cause of chronic hepatitis, liver cirrhosis, and liver cancer. This vaccine plays a key role in reducing liver-related complications and deaths worldwide.
Types of Hepatitis A and B Vaccines and Their Differences
There are three main types of hepatitis vaccines: the hepatitis A vaccine, the hepatitis B vaccine, and the combined A–B vaccine that protects against both viruses in a single shot.
The hepatitis A vaccine is made from an inactivated virus, which helps the body build immunity without causing illness. The hepatitis B vaccine is produced using recombinant DNA technology, containing only the surface protein of the virus — making it both safe and effective.
The combined A–B vaccine merges protection against both types of hepatitis, ideal for adults who have never been vaccinated or prefer a more convenient schedule. It is typically given in a 3-dose series as recommended by healthcare professionals.
What Is the Recommended Age to Get the Hepatitis Vaccine?
Hepatitis vaccination can start in early childhood. The hepatitis B vaccine is part of the routine immunization schedule and is given to newborns within 24 hours of birth, followed by the second and third doses at doctor-recommended intervals to ensure long-term immunity.
The hepatitis A vaccine is recommended for children aged 1 year and older, as well as for adults who have never been vaccinated — especially those at higher risk, such as travelers to endemic regions, healthcare workers, and people with chronic liver disease.
Adults uncertain about their vaccination history can undergo an antibody test to check their immunity level and determine if additional vaccination is needed under medical advice.
How Many Doses of the Hepatitis Vaccine Are Needed, and How Far Apart?
The number of doses depends on the vaccine type. The hepatitis A vaccine requires two doses, spaced 6–12 months apart, to achieve long-lasting immunity.
The hepatitis B vaccine is given as a three-dose series on a 0–1–6 month schedule (first dose, one month later, and six months after the first dose). This ensures complete and durable protection against the virus.
For the combined hepatitis A–B vaccine, the same 0–1–6 month schedule applies. In specific situations, an accelerated schedule (0–1–2 months) may be used for rapid protection — but only under medical supervision.
What Are the Side Effects of the Hepatitis Vaccine?
Hepatitis vaccines are highly safe and approved by the World Health Organization (WHO) and Thailand’s Ministry of Public Health. Most side effects are mild and temporary, such as pain, redness, or swelling at the injection site.
Some people may experience mild fever, fatigue, or muscle aches after vaccination — normal immune responses that typically resolve within a day or two.
Severe allergic reactions are extremely rare. However, if you experience symptoms such as significant swelling, difficulty breathing, or widespread rash, seek medical attention immediately for proper evaluation and care.
How to Take Care of Yourself After a Hepatitis Vaccination
After receiving a hepatitis vaccine, stay at the clinic for 15–30 minutes to monitor for any immediate allergic reactions such as dizziness or shortness of breath. You may then resume normal daily activities.
Avoid heavy exercise or lifting weights during the first 24 hours, as this may worsen soreness at the injection site. Drink plenty of water, get adequate rest, and take paracetamol if you experience mild fever or arm pain.
If you develop unusual symptoms such as severe swelling, high fever, or a rash, seek medical attention promptly for evaluation and appropriate care.
Who Should Not Get the Hepatitis A–B Vaccine?
While hepatitis vaccines are safe for most people, certain groups should avoid or postpone vaccination. These include individuals with a history of severe allergic reactions to vaccine components — such as yeast protein or specific preservatives used in the formulation.
People who are acutely ill, have a high fever, or are recovering from illness should wait until fully recovered before receiving the vaccine to ensure the best immune response.
Pregnant women and individuals with severe chronic diseases or weakened immune systems should consult their doctors before vaccination to assess individual safety and suitability.
Where to Get the Hepatitis Vaccine and How to Prepare
Hepatitis vaccination should be administered at certified medical facilities under the supervision of qualified healthcare professionals to ensure safety and proper cold-chain storage of the vaccine.
Before vaccination, inform your doctor if you have any chronic illness, allergies, or a history of vaccine reactions. Get adequate rest, avoid fasting, and ensure your body is in good condition prior to the appointment.
You can receive the hepatitis A–B vaccination at Safe Clinic, where specialized doctors provide consultation, proper vaccine management, and comprehensive aftercare for your peace of mind.
Conclusion
Vaccination against hepatitis A and B is currently the most effective method to prevent liver disease caused by viral infection. It significantly reduces the risk of chronic hepatitis, liver cirrhosis, and liver cancer.
These vaccines stimulate the body’s immune system to produce specific antibodies. When administered according to the recommended schedule, immunity can last for many years — and in some individuals, possibly for life.
While vaccination cannot prevent liver diseases caused by other factors such as alcohol or fatty liver, it remains a vital preventive measure to protect long-term liver health and reduce the risk of serious complications.
FAQ
How many years does the hepatitis A–B vaccine protect against?
Hepatitis A vaccine immunity typically lasts around 15–20 years or longer, while hepatitis B vaccine protection usually lasts at least 20 years — and in some cases, for life.
If I have been infected with hepatitis, do I still need to get vaccinated?
People who have previously had hepatitis A are naturally immune and don’t need the vaccine. Those who have had hepatitis B should get a blood test to check antibody levels before deciding on further vaccination.
Can the hepatitis A and B vaccines be administered at the same time?
Yes. Combined hepatitis A–B vaccines are available and can safely protect against both viruses in a single injection, under medical supervision.
Should young children and the elderly be vaccinated?
Infants should receive the hepatitis B vaccine at birth, and children over one year can get the hepatitis A vaccine. Older adults who haven’t been vaccinated should consult a doctor before receiving it.
Is the hepatitis A–B vaccine safe for pregnant women?
In general, hepatitis A–B vaccination is postponed until after pregnancy unless urgently needed — for example, before traveling to high-risk areas. Always consult a doctor beforehand.
References
- World Health Organization (WHO) — Hepatitis A and B vaccines: Position Paper, 2024.
- Centers for Disease Control and Prevention (CDC) — Hepatitis A and B Vaccination Guidelines.
- Centers for Disease Control and Prevention (CDC) — hepatitis b vaccine recommenced
- World Health Organization (WHO) — Position paper hepatitis b vaccine
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Medical Reviewer: Dr. Chaiwat Songsiriphan
Expertise: Specialist in Dermatology and Venereology (STDs)
Over 10 years of clinical experience
Latest Article Updates: April 16, 2026
