A method of producing viral gene delivery vehicles which can be transferred to pre-selected cell types by using targeting conjugates. The gene delivery vehicles comprise: 1) the gene of interest 2) a viral capsid or envelope carrying a member of a specific binding pair, the counterpart of which is not directly associated with the surface of the target cell. These vehicles can be made unable to bind to their natural receptor on the cell. The targeting conjugates are composed of the counterpart member of the specific binding pair linked to a targeting moiety which is a cell-type specific ligand. The number of the specific binding pair present on the viral vehicles can be, for example, an immunoglobulin binding moiety, biotin, avidin, or streptavidin. The outer membrane or capsid of the virus may contain a substance which mediates entrance of the gene delivery vehicle into the target cell. Due to the specificity of the ligand, the high affinity of the binding pair and to the inability of the gene delivery vehicle to be targeted when used alone, the universality of the method for gene delivery, together with its high cell type selectively can easily be achieved by the use of various adequate targeting conjugates.
