The Hepatitis B virus (HBV) is a cause of liver disease. In some cases, HBV can be a short-lived, acute infection, but in others it can become a life-long, chronic condition and lead to cirrhosis of the liver, cancer of the liver, liver failure and death.
HBV is transmitted through activities that lead to contact with the blood, semen or other bodily fluid of an infected person. Some modes of transmission include:
The most effective way to protect against HBV infection is to get vaccinated. People who are at risk of HBV infection and should consider vaccination include the following:
For full protection against HBV, vaccination involves three to four injections of the HBV vaccine, which are administered over the course of four to six months. Follow-up blood tests are available for people to check they have responded to the vaccine and five-year booster injections are advised for people who are thought to be at ongoing risk.
HBV tests are given to pregnant women as part of routine antenatal care. There is no live virus in the vaccine and no apparent risk of damaging side effects to the fetus while it is developing in the womb.
Babies born to infected mothers must be administered a dose of HBV vaccine within 24 hours of being born, with further doses administered at one, two and 12 months of age. Mothers who have been identified as particularly infectious, may be given an injection of antibodies called hepatitis B immune globulin (HBIG) in addition to the vaccine, which provides rapid protection.
If a person is exposed to the HBV virus and has not previously been vaccinated, they should seek immediate medical advice, as they may benefit from the HBV vaccine. In some cases, an HBIG injection may also be given.
The HBV vaccine is a very safe vaccine that does not usually cause any problems other than redness and soreness at the injection site. Other side effects are rare, but, as with any medicine, there is a risk of a serious allergic reaction, which is thought to occur in about one in 1.1 million doses.