On May 29, 2020, Moderna announced the first participants in each age cohort had been dosed in the Companyﾒs Phase 2 study of its mRNA vaccine candidate (mRNA-1273) against the novel coronavirus (SARS-CoV-2).

The Company planned to enroll 600 healthy participants across two cohorts of adults ages 18-55 years and older adults ages 55 years and above. Each participant will be assigned to receive placebo, a 50 ﾵg or a 100 ﾵg dose at both vaccinations. Participants will be followed through 12 months after the second vaccination.