Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease.

Hepatitis B can be prevented by vaccines that are safe, available and effective.

WHO recommends that all infants receive the hepatitis B vaccine as soon as possible after birth, preferably within 24 hours, followed by 2 or 3 doses of hepatitis B vaccine at least 4 weeks apart to complete the vaccination series. Protection lasts at least 20 years and is probably lifelong.

The virus is most commonly transmitted from mother to child during birth and delivery, as well as through contact with blood or other body fluids, unsafe injections or exposures to sharp instruments.

Most people do not experience any symptoms when newly infected.

Some people have acute illness with symptoms that last several weeks, such as yellowing of the skin and eyes, dark urine, tiredness and pain in the abdomen.

When severe, acute hepatitis can lead to liver failure and death.

Although most people will recover from acute illness, some people with chronic hepatitis B will develop progressive liver disease and liver disease which can be fatal.