Disclosed herein are nucleic acid molecules comprising one or more nucleic acid sequences that encode a modified consensus MUC16 antigen. Vectors, compositions, and vaccines comprising one or more nucleic acid sequences that encode a modified consensus MUC16 antigen are disclosed. Methods of treating a subject with a MUC16-expressing tumor and methods of preventing a MUC16-expressing tumor are disclosed. Modified consensus MUC16 antigen is disclosed.