An mRNA vaccine against SARS-CoV-2 - Preliminary report

A candidate vaccine against SARS-CoV-2 is mRNA-1273 that is a lipid nanoparticle-encapsulated, nucleoside-modified mRNA based vaccine. The encoded gene is SARS-CoV-2 spike protein stabilized in its prefusion conformation, which is designed by substituting two amino acids positions 986 and 987 to prolines. The first-in-human phase 1 clinical trial in healthy adults was performed, and the interim results were reported.  Forty-five adults were inoculated with mRNA-1273 via deltoid muscle injection. Several adverse events were observed, whereas they were mild or moderate. Production of neutralizing antibodies against SARS-CoV-2 was confirmed in all participants. The phase 2 trial is ongoing, moreover, a large phase 3 trial is anticipated to begin during the summer of 2020.