The hepatitis B vaccine is an injectable vaccine containing the outer cell wall of the hepatitis B virus. This induces the production of the antibodies that attack the outer cell wall without risking infecting the patient with the disease. Unlike most vaccines, it is not effective after a single dose and requires a course of 2-3 injections separated by a time period of one month between the first two and six months between the last two. A blood test is usually performed some time after the second injection to ensure the antibodies are present. However, once the antibodies are present, the protection against the virus lasts indefinitely.
It is not routinely given as part of a vaccination schedule in most countries. However, if an infant is born to a mother with hepatitis B, the child is given the immunization as it will still be effective to prevent the disease developing in the child. It is also commonly given in countries where hepatitis B is endemic, or to people who wish to travel to such areas. In most countries, medical staff has to prove that they have been vaccinated. It is also recommended for patients with diabetes mellitus. Although it was once feared it was associated with certain demylinating diseases, it is now believed that the vaccine was not responsible and that it is generally safe with a very low risk of side effects.