In certain embodiments, methods and compositions are provided for generating immune responses against tumor neo-antigens or neo-epitopes. In particular embodiments there may be provided methods for constructing and producing recombinant adenovirus-based vector vaccines containing nucleic acid sequences encoding tumor neo-antigens and neo-epitopes that allow for vaccinations in individuals with preexisting immunity to adenovirus. In additional embodiments, methods and compositions are provided for the treatment of cancer using immunotherapy based on recombinant adenovirus-based vectors combined with engineered natural killer cells. In some embodiments, the methods and compositions further comprises a nucleic acid encoding for an immunological fusion partner.