Biosafety and Viral Gene Transfer Vectors

This chapter provides a general overview of the construction, safety features, and suggested containment level of viral gene transfer vectors in common laboratory use or under development. The discussion of each vector focuses on similarities of the biosafety features and issues arising from the construction and use of these gene transfer systems. The safety assessments and suggested containment levels presented in the chapter can be used to inform the discussions of local institutional biosafety committees (IBCs), investigators, and biosafety professionals, and assist in the assessment of the risks inherent in the use of these vectors in the laboratory. Characteristics of viral systems commonly used for recombinant gene transfer have been provided in the chapter. Replication-defective vector genomes persist in one of two forms in the infected cell: either as an episome or integrated into the host cell genome. In this discussion, an episomal viral vector means that the vector genome remains intact yet is separable from the host cell DNA by physical methods.