This page provides a brief summary of the disease and the vaccine that is available to prevent it. Links to more detailed information are provided at the bottom of the page.
What is Hepatitis B?
Hepatitis B is a viral disease that attacks the liver and may cause jaundice (yellow skin and eyes). In most people the virus clears up within 6 months and they become immune to any further hepatitis B infection. But some people (about one in ten of those who get Hepatitis B as an adult) remain infectious and may go on to develop cirrhosis or cancer of the liver over a period of years. Follow up is therefore important to detect early changes to the liver and treat when necessary.
Hepatitis B is preventable by using a safe and effective vaccine.
Who is most at risk of getting Hepatitis B?
Hepatitis B is caused by a virus which has been found in many body fluids, e.g. sweat, tears, saliva, semen and vaginal secretions but infected blood is the most common way that the virus is transmitted from one person to another. This is why some groups are at a higher risk of catching the disease, e.g.
- Babies born to infected mothers,
- Those with specific medical conditions e.g. severe kidney disease, HIV infection
- Household contacts and sexual partners of infected people,
- Families adopting children from countries with high rates of infection
- People with a learning disability who attend an institution.
What are the symptoms of Hepatitis B?
Some people who have acute Hepatitis B have no symptoms at all and others may have a severe illness that requires hospitalisation.
Symptoms that may occur include
- Jaundice (yellow skin and eyes),
- Itchy skin,
- Fatigue and tiredness,
- Poor appetite and weight loss,
- Diarrhoea or Vomiting,
- Joint pains
What is the incubation period for Hepatitis B?
Illness may develop 2 to 6 months after exposure, usually within 2-3 months. The virus may be found before symptoms appear and may persist for several months.
How does Hepatitis B illness develop?
Some people may not clear the virus from their system and become chronic carriers for life with an ongoing risk of infecting others. Less than 10% of those infected as adults and approximately 90% of those infected in infancy will go on to develop a chronic form of the disease.
How serious is Hepatitis B?
Long-term infection with hepatitis B can cause liver disease. This can lead to death from liver cancer or cirrhosis. About 1 in 4 chronic carriers will develop cirrhosis or liver cancer.
Hepatitis B is particularly likely to cause long term infection in babies and children.
Who should get Hepatitis B vaccine?
Hepatitis B can be prevented by vaccination.
Hepatitis B vaccine is given to children as part of the 6 in 1 vaccine at 2, 4 and 6 months of age. Children whose mothers have a known hepatitis B infection are also recommended the hepB vaccine at birth.
The 6 in 1 vaccine protects against infection caused by hepatitis B, tetanus, diphtheria, Hib (Haemophilus Influenzae b) pertussis (Whooping Cough) and polio.
Who is recommended to get a catch up Hepatitis B vaccine?
Vaccination is recommended for people in at risk groups.
The National Immunisation Advisory Committee (40.9KB) does not recommend catch up vaccines for people who are not in at risk groups.
Who should not get Hepatitis B vaccine?
There are very few people who should not get Hepatitis B vaccine. Your child should not get the vaccine if they have had a severe allergic reaction (anaphylaxis) to a previous vaccine or any part of a vaccine.
What to expect after getting Hepatitis B vaccine?
Hepatitis B vaccine is very safe. The commonest reactions are discomfort, redness and swelling at the injection site.
Very occasionally fever, rash, tiredness and flu-like symptoms may occur.
If the person intending to be vaccinated is pregnant or thinks they may be pregnant, it is advisable to discuss this with your family doctor before availing of the vaccination.
How effective is the Hepatitis B vaccine?
98% of children become immune to Hepatitis B after completing the recommended vaccine course.
Where can I find out more?
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This page was updated on 22 March 2023