Chapter 1. Introduction: The Marathon of the Messenger RNA -- Part I. Messenger RNA, an essential role and challenge -- Chapter 2. A short history of vaccination -- Chapter 3. From DNA to RNA -- Chapter 4. Messenger RNA (mRNA): from transcription to protein translation -- Chapter 5. The mechanism of viral infection -- Chapter 6. The immune response -- Part II. From preliminary studies to clinical trials -- Chapter 7. Promising studies in the 1990s -- Chapter 8. The use of mRNA - the initial technical obstacles -- Chapter 9. The birth of CureVac: the era of the pioneers -- Chapter 10. Solutions for mRNA optimization -- Chapter 11. Modified and unmodified mRNA: for what purpose? -- Chapter 12. Experiments and clinical trials conducted: the power of therapeutic mRNA -- Chapter 13. Experiments and clinical trials against infectious diseases -- Chapter 14. Experiments and clinical trials against cancer -- Chapter 15. Experiments and clinical trials carried out in other therapeutic fields -- Chapter 16. Modified mRNA versus unmodified mRNA: not just a scientific issue -- Part III. The triumph of messenger RNA -- Chapter 17. A very progressive diffusion in scientific circles -- Chapter 18. The development of future biotechs in the 2010s -- Chapter 19. The importance of intellectual property and patents -- Chapter 20. 2020: the triumph of anti-Covid mRNA vaccines -- Chapter 21. mRNA, a technology of the future.