The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to notable advancements in the pharmaceutical sector regarding the development of mRNA vaccines. These vaccines have gained considerable attention given their straightforward production process, improved safety profile compared to DNA vaccines, and efficient expression of mRNA-encoded antigens within cells. In addition, mRNA vaccines offer the advantage of not requiring transcription within the nucleus, thereby eliminating the risk of integration into the host genome. Nevertheless, mRNA vaccines also have limitations, such as possible allergy, kidney failure, and other serious side effects, or may rapidly degrade after injection or cause a cytokine storm. These factors present substantial challenges concerning the immunogenicity and delivery of mRNA vaccines. The purpose of this article is to primarily focus on the molecular design, delivery systems, and current clinical status of mRNA vaccines, aiming to provide valuable insights for future advancements in this field.