In-vivo effect of the ORF7b deletion. Golden Syrian hamsters were infected with 104 PFU of rSCV and r7bΔTMD (x-axis). Heat inactivated rSCV served as mock control. For each point of time post infection, three animals per virus variant were sacrificed (animals 1, 2, 3 as identified on the x-axis). Lungs were taken in total. Viral titers were determined by plaque assay and viral RNA was quantified by real-time RT-PCR. Light grey bars represent log copies of viral RNA, dark grey bars represent PFU per g lung tissue. The arrow indicates one animal with failure of virus replication.