What describes naked DNA vectors in gene therapy?

Naked DNA vectors are characterized by the fact that they do not integrate into the genome of the target cells. Instead, they exist as episomal DNA within the cell, which means they are maintained separately from the host's chromosomal DNA. This lack of integration can lead to transient expression of the gene of interest, as the DNA may eventually degrade or be lost during cell division.

Other options refer to characteristics of different types of vectors used in gene therapy. For example, some vectors are designed to specifically target particular types of cells, which naked DNA vectors do not inherently do. Likewise, certain vectors may provoke an immune response, a concern primarily associated with viral vectors or those that can stimulate inflammation. Lastly, while efficiency can vary widely depending on the method of delivery and the target cells, naked DNA vectors are generally considered less efficient when compared to viral vectors, which can deliver genes more effectively and maintain longer-term expression. This context highlights how naked DNA vectors play a unique role in gene therapy, primarily due to their non-integrating nature.