Progress and challenges of mRNA vaccines

Abstract Messenger RNA (mRNA) vaccines are third‐generation nucleic acid vaccines developed after first‐generation inactivated and live‐attenuated vaccines and second‐generation subunit and viral vector vaccines, characterized by a rapid response to pathogen mutation, simple production process, and high production capacity. The basic mechanism through which mRNA vaccines provide immune protection is the introduction into the body of mRNA expressing a target antigen through a specific delivery system and expression of the corresponding protein in vivo, which stimulates a specific immunological response. Multiple mRNA vaccine platforms against infectious diseases and cancers have shown encouraging results in both animal models and human subjects; in particular, mRNA vaccines against COVID‐19 have been widely adopted around the world. However, the development of mRNA vaccines has not been straightforward. The rapid progress of mRNA vaccines would not have been possible without major recent advances in innate immune sensing and in vivo delivery strategies. Creative research in mRNA design, lipid/polymer/novel nanocarrier development, and coupling to wearable/implantable electrostimulation medical devices may drive the evolution of mRNA vaccines.