A: Hepatitis B is caused by the hepatitis B virus (HBV).
The virus interferes with the functions of the liver and activates the immune system, which produces a specific reaction to combat the virus.
As a consequence of pathological damage, the liver becomes inflamed.
A small percentage of infected people cannot get rid of the virus and become chronically infected – these people are at high risk of death from cirrhosis of the liver and liver cancer.
Hepatitis B virus is transmitted by contact with blood or body fluids of an infected person – the same way as the human immunodeficiency virus (HIV). However, HBV is 50 to 100 times more infectious than HIV.
The main ways of getting infected with HBV are:
- perinatal (from mother to baby at the birth)
- child-to-child transmission
- unsafe injections and transfusions
- sexual contact.
Worldwide, most infections occur from mother-to-child, from child-to-child (especially in household settings), and from reuse of unsterilized needles and syringes.
Before the widespread use of the hepatitis B vaccine, almost all children in developing countries used to become infected with the virus.
You can protect yourself against hepatitis B by being vaccinated.
The hepatitis B vaccine has an outstanding record of safety and effectiveness, and since 1982, over one billion doses have been used worldwide.
The vaccine is 95% effective in preventing chronic infections from developing.
Protection lasts for 20 years at least, no booster is recommended by WHO as of today.