Recent Advances in Adenovirus-Vectored Vaccines Development

Recombinant adenovirus-vectored vaccines based on human adenovirus serotype 5 (HAdV-5) have been extensively studied both pre-clinically and in clinical trials for the past 25 years. Initially, they were considered as the most promising platform for human immunodeficiency virus (HIV) vaccine development. However, HAdV-5-based vaccine did not meet expectations in a large-scale clinical trial called STEP trial. In that trial, the vaccine not only showed lack of efficacy, but also suggested an increased trend for HIV acquisition in individuals with pre-existing HAdV-5 neutralizing antibodies.