ABSTRACT
mRNA vaccines offer enormous promise in the fight against cancer and viral diseases, due to their superiority in terms of efficacy, safety, and industrial manufacturing. In the last few decades, sequence optimization has resulted in the development of several types of mRNAs to solve the disadvantages of high mRNA immunogenicity, instability, and inefficiency. mRNA vaccines are combined with immunological adjuvants and various delivery techniques based on immunological studies. By using mRNA-delivery techniques, mRNA efficiency and stabilization can be increased aside from sequence optimization. Increased antigen reactivity provides an understanding of mRNA-induced immunity, both innate and adaptive, without the need for antibody-dependent enhancing activity. Therefore, scientists have turned to carrier-based mRNA vaccines, dendritic cell-based mRNA vaccines, and naked mRNA vaccines to solve the problem. The molecular mechanism of mRNA vaccines and the underlying process will be discussed in this chapter, delivery strategies, and relevance to Corona Virus Disease 2019 (COVID-19). © 2022 Nova Science Publishers, Inc.