This article, from Vrinda Gote et al., published in the International Journal of Molecular Sciences, provides a comprehensive overview of mRNA vaccines. It covers the structure of mRNA, the role of modified nucleotides, and the mechanisms by which mRNA vaccines stimulate both the innate and adaptive immune systems. The article goes on to examine the use of lipid nanoparticles for mRNA delivery, including different types of lipids and their role in the formulation of LNPs. The authors explore the manufacturing process for mRNA vaccines, highlighting key steps such as upstream production, downstream purification, and formulation. Finally, the article discusses the current status of mRNA vaccines in clinical trials, the development of second-generation mRNA vaccines, and the potential shortcomings of mRNA vaccines.