**1. Introduction**

Adenoviruses (Ads) are non-enveloped, icosahedral DNA viruses with virion size ranges between 70 and 90 nm [1]. They belong to a diverse family (>50 serotypes) of DNA viruses called adenoviridae. Adenovirus was first isolated from human adenoid tissues in 1953 by

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Rowe and his colleagues [2]. Adenoviruses usually cause non-symptomatic respiratory tract infections in both human and animals but can be life-threatening to immunocompromised individuals. Certain human adenovirus serotypes are ubiquitous in children, and most adults carry neutralizing antibodies to adenoviruses [3]. Nonetheless, since their initial use in gene therapy, they have gained wide recognition as a vaccine antigen delivery vehicle and have proven to be safe and efficient vaccine vectors for eliciting protective immune responses against transgene antigens in many animal and human studies. Recently, adenovirus vectors have been employed to attack cancer cells in cancer therapy [4]. In this chapter, we introduce different adenoviruses and their biology and potential for use in gene delivery, vaccine, and therapeutics in several human diseases. In addition, we will discuss their limitations and future prospects.
