An Evidence Based Perspective on mRNA-SARS-CoV-2 Vaccine Development

Abstract

The first outbreak of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurred in Wuhan, Hubei Province, China, in late 2019. The subsequent COVID-19 pandemic rapidly affected the health and economy of the world. The global approach to the pandemic was to isolate populations to reduce the spread of this deadly virus while vaccines began to be developed. In March 2020, the first phase I clinical trial of a novel lipid nanoparticle (LNP)-encapsulated mRNA-based vaccine, mRNA-1273, which encodes the spike protein (S protein) of SARS-CoV-2, began in the United States (US). The production of mRNA-based vaccines is a promising recent development in the production of vaccines. However, there remain significant challenges in the development and testing of vaccines as rapidly as possible to control COVID-19, which requires international collaboration. This review aims to describe the background to the rationale for the development of mRNA-based SARS-CoV-2 vaccines and the current status of the mRNA-1273 vaccine.

Figure 1

Schematic diagram of the mRNA-based vaccine targeted to the spike protein (S protein) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The mRNA-based vaccine targeted to the S protein of SARS-CoV-2 works by active immunization. This technique will not use part of the virus but only recombine mRNA of the S protein in vitro according to the gene sequence, which is coated with lipid nanoparticles for effective delivery. Once injected into the muscle, the myocytes take up the lipid nanoparticle (LNPs) and then release the mRNAs into the cytoplasm for translation into the S proteins. These endogenously synthesized S proteins will be secreted to activate both humoral and cellular immune responses. S protein – spike protein; IM – intramuscular, LNP – lipid nanoparticle; DC – dendritic cell; MHC – major histocompatibility complex; Ag – antigen.