What are adenoviruses (Ads) and why are they used as vectors?

Adenoviruses (Ads) are double-stranded non-enveloped DNA viruses which are highly infectious but also highly immunogenic. This means that while transduction efficiency can be potentially very high, there is also a high risk that immune activation will eliminate viruses before they reach their target, or eliminate transduced cells prior to transgene activation and transcription.1 In addition, most individuals are infected with at least one adenovirus serotype early in life, leading to widespread pre-immunity. This limits the efficacy of adenovirus vectors for therapeutic usage.1 For a further look into relevant areas and viral vectors please visit our resource center here.

References:
1. W.S.M. Wold and K. Toth, “Adenovirus Vectors for Gene Therapy, Vaccination and Cancer Gene Therapy,” Curr Gene Ther 13(6): 421-433, 2013.