The Immunoshift technology developed by VCN scientists has achieved functional deletions on immunodominant T-cell epitopes present in oncolytic adenovirus, which allows a more efficient triggering of anti-tumor immune responses. Of note, these functional T-cell epitopes deletions are not associated with reduced cytotoxicity or reduced viral replication in comparison to a parental adenovirus. Oncolytic adenovirus including immunoshift technology are able to mount anti-tumor immune responses in a more efficiently compared to non-modified counterparts, when tested both in a model of tumor-challenge vaccination or in an established tumor model.