Seoul virus (SEOV) is one of the four known hantaviruses causing hemorrhagic fever with renal syndrome (HFRS). A replication-competent recombinant canine adenovirus type 2 expressing the Gc protein of SEOV (rCAV-2-Gc) in BALB/c mice induced complete protection against a intensive infectious challenge with ~1,000 50% infective doses (ID50) for SEOV strain CC-2 (Yuan et al., 2010).