The propagation of AAV in tissue culture requires the help of another virus in which adenovirus (AdV) and herpes virus (HSV) are traditionally used as AAV helper viruses. The AAV vector is a recombinant variant of the wild-type AAV virus in which the native coding region and the non-coding region have been replaced by the gene of interest. The vector genetic construct retains the lateral ITR, which is the only cis-acting element required for AAV DNA replication and encapsidation. Through these modifications, recombinant adeno-associated viruses (rAAV) becomes a replication-defective entity that can only infect cells and deliver DNA to the nucleus.
https://www.creative-biolabs.com/vaccine/adeno-associated-virus-AAV-as-vaccine-vectors.htm
