Figure 5-1.3.2(a): Strategy for engineering a virus into a vector.

(Adapted from Kay MA, Glorioso JC, Naldini L. 2001. Viral vectors for gene therapy: the art of turning infectious agents into vehicles of therapeutics. Nature Medicine, 7(1).)

Transgene may be incorporated into viral vectors either by addition to the whole genome or by replacing one or more viral genes which can be generally achieved by ligation or homologous recombination.