Medical researchers first began evaluating mRNA as a therapeutic modality in the 1990s. The clinical use of mRNA is presently being evaluated in both therapeutic (protein replacement therapies, and as an alternative to classical gene therapies) and preventive (mRNA vaccines) roles. There are over 65 mRNA therapeutics and more than 85 vaccines currently in the development pipeline. As a biomolecule, mRNA is well tolerated in vivo, and (depending on the encoded protein) is capable of inducing humoral and cell-mediated immune responses. Moreover, using this approach, researchers have demonstrated that it is possible to deliver adequate amounts of tumor antigens (bearing patient-specific molecular signatures), and provide the necessary costimulatory signals to mount an effective anticancer immune response. As indicated earlier, mRNA-based interventions are also being evaluated as protein replacement therapies and alternatives to classical gene therapies; however, research on the aforementioned modalities is still in its infancy, with several potential leads in the preclinical stages. Such therapies are predominantly being developed for treating rare disorders. On the other hand, using mRNA, it is possible to develop both personalized (for various cancer) and general-use vaccines (for infectious diseases). Interestingly, mRNA vaccines have shorter development and manufacturing timelines, compared to their traditional counterparts. In fact, Pfizer and BioNtech’s recently approved vaccine (BNT-162) and Moderna’s late phase candidate (mRNA-1273) against the novel coronavirus strain, are both mRNA-based preventive solutions.