Lamivudine and adefovir dipivoxil are the two anti-viral agents that can suppress the replication of the virus. However, these drugs using either alone or in combination only induce HBeAg seroconversion in less than 20% of patients. Most patients therefore required long-term treatment, which has a risk of development of drug resistance. Premature cessation of these anti-viral agents is usually accompanied by relapse of viraemia and hepatitis.