The disclosure relates to cancer ribonucleic acid (RNA) vaccines, as well as methods of using the vaccines and compositions comprising the vaccines. In particular, the disclosure relates to concatemeric mRNA cancer vaccines encoding several cancer epitopes on a single mRNA construct, i.e. poly-epitope mRNA constructs or poly-neo-epitope constructs. The disclosure further relates to p53 and KRAS mutations, as well as incorporation of immune enhancers such as STING, e.g. mRNA constructs further encoding an immune stimulator or adjuvant. The disclosure further relates to inclusion of universal T cell epitopes, such as tetanus or diphtheria toxins to elicit an enhanced immune response.