From Design to Clinical Use: mRNA Vaccines for Infectious Diseases and Cancer

mRNA vaccines represent a revolutionary advance in vaccinology, boasting advantages like rapid development, robust immunogenicity and flexible antigen design over traditional vaccines. This review systematically summarizes the core research progress of mRNA vaccines, including their structural composition with five functional elements and novel subtypes (linear mRNA, self-amplifying RNA, circular RNA) with unique biological characteristics and application value. It elaborates on the immune activation mechanism of mRNA vaccines, which mimic natural viral infection to trigger both innate and adaptive immunity, and analyzes mainstream delivery systems (lipid nanoparticles, dendritic cells, protamine, exosomes, polymers) with their respective performance, advantages and bottlenecks. This review also details the clinical application status of mRNA vaccines in infectious diseases (influenza, rabies, monkeypox, SARS-CoV-2, HIV, parasites) and cancer therapy, highlighting promising preclinical and clinical results of candidate vaccines and combined therapeutic regimens. Additionally, it addresses the current limitations of mRNA vaccines, such as delivery inefficiency, production costs, and cold chain constraints. Finally, this review prospects the future development direction, emphasizing that the optimization of delivery systems, antigen design and production processes will further promote the clinical translation and diversified application of mRNA vaccines in disease prevention and treatment.