In many countries where 8% to 15% of children used to become chronically infected with HBV, the rate of chronic infection has been reduced to less than 1% in immunized groups of children.

• 在许多国家，曾经有8%25至15%25的儿童慢性感染，现在，在免疫的儿童群体中，降低至小于1%25的儿童慢性感染。