... generation of recombinant MVA [43,44]. While the BAC technology offers the advantage of targeting any genomic locus of MVA, the method is dependent on the use of a helper virus, and results in recombinants ... detected in the dMVA-ZG stock confirming therefore the purity of the defective virus. Figure 4 PCR analysis of the D4R deletion in the defective virus dMVA-ZG. Genomic DNA of dMVA-ZG was subjected ... host range selection system. a. Schematic representation of the plasmid pDM-Zgpt for the construction of the D4R- deleted dMVA-ZG, and the corresponding insertion locus in the genome of MVA. b....