HBV HBV genotype B virus was obtained by ultracentrifugation of plasma from an HBV chronic carrier with written consent. HBV genotype D virus was produced by transfection of Huh-7 cells with a plasmid containing 1.05 copies of HBV genome under the control of a CMV promoter similarly as previously described by Blanchet and Sureau (2006) . The Genebank accession numbers for the viruses are JX978431 and U95501.1, respectively.