Young children (this includes babies) who become infected with hepatitis B are more likely to go on to develop chronic infection than adults. In children under the age of one year, nine out of 10 of them who are infected will become chronically infected.
For children between one and four years of age the risk is slightly lower at 30-50%.
Children infected at birth are at greater risk of becoming chronic carriers – possibly nine out of every 10 of them. This also increases their chances of developing chronic liver disease that can in turn cause premature death. However, early intervention with immunisation is successful in 95% of cases, preventing children from becoming carriers and drastically reducing the risk of liver disease.