Moderna Inc. finalized its design for mRNA-1273, its COVID-19 vaccine, on Jan. 13, 2020, two days after Chinese scientists published the coronavirus's genetic sequence online. The first clinical batch of the vaccine was completed on Feb. 7 and shipped on Feb. 24 in preparation for human trials, which commenced with the first dose on March 16.
According to a University of Virginia medical professor, the new class of mRNA vaccines—which include the Moderna and Pfizer vaccines against COVID-19—are faster to develop in labs since they do not require the production of weakened pathogens or proteins as traditional vaccines do. They still must be tested in carefully-managed trials across diverse demographic groups to confirm their safety and efficacy, which limits how fast they can be deployed against a new health threat.