An adenoviral vector is disclosed that includes two adenoviral ITRs, wherein the two adenoviral ITRs flank a packaging signal and a single retroviral LTR operably linked to a nucleic acid sequence of interest, wherein the adenoviral vector does not include a nucleic acid sequence encoding the retroviral structural proteins and wherein the adenoviral vector does not include a second retroviral LTR. In one embodiment, a method for transforming a cell is disclosed. In another embodiment, a method is disclosed for introducing a transgene into a cell with a single viral vector. In a further embodiment, a method is provided for preventing or treating disorder in a subject. A pharmaceutical composition is also provided.