Growth kinetics of MVA and dMVA-ZG. cDF-1 cells were infected with the defective virus dMVA-ZG at moi = 0.05. For comparison, infections of DF-1 cells dMVA-ZG and with wild-type MVA were performed in parallel. Cells were harvested at the indicated time points and the viral titers were determined by TCID50 titration. Mean values ± SEM are shown (n = 6).