Human kidney cells (AD-293) were used to grow recombinant replication-defective human adenoviruses (rAd5) and determine virus titers. BHK-21 cells were used to grow FMDVand determine virus infectivity. Both of the cell lines were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% heat-inactivated fetal bovine serum (pH 7.4). Cultures were incubated at 37°C with 5% CO 2 . Two FMDV isolates of serotype O (HKN/2002 (GenBank accession number AY317098) and CHA/ 99 (GenBank accession number AJ539138)) and two FMDV isolates of serotype Asia I (YNBS/58 (GenBank accession number AY390432) and Jiangsu/ 2005 (GenBank accession number EF149009)) were used for viral challenge.