Therefore, lab methods often utilize minimal fragments of the helper DNA that can serve this purpose without creating unwanted virus.
Within the family parvoviridae, the dependovirus genus was given a distinct classification due to their dependence on another virus.
The most widely known dependovirus is adeno-associated virus (AAV) which was originally discovered as a contaminant in a sample of simian adenovirus.
[5] Though AAV is considered to be dependent on adenovirus, it is able to replicate in the presence of herpesvirus as well as certain cytotoxic events such as UV irradiation or some carcinogens[6] During the course of a natural dependovirus infection, if the helper virus is not present, the dependovirus is often capable of integrating into the host genome and going into a latent phase of its life cycle—effectively waiting for the next helper virus infection.
Because AAV can deliver transgenic material in a non-replicating form, it is a strong candidate for gene therapy and is currently used in about 8% of clinical trials.