Comment Not giving people wild-type HIV (Score 2) 201
The viral vectors are based on replication-deficient HIV. They are missing some of the genes necessary for their replication. They cannot (or at least should not) be able to reproduce in the cells, so they are not giving people AIDS. One of the reasons HIV is used because it is a lentivirus, which means it can integrate into the genomes of cells that are not actively dividing.