On Jul. 8, 2020, Moderna announced that it had completed enrollment for both cohorts of the Phase 2 study of its vaccine candidate (mRNA-1273) against COVID-19. mRNA-1273 was Moderna’s second mRNA vaccine for an infectious disease to complete enrollment of a Phase 2 study, following the Company’s CMV Phase 2 study, which was fully enrolled on Mar. 3, 2020.

On June 11, 13 days after the first participant was dosed, the Company announced that the cohort of healthy younger adults ages 18-55 (n=300) and the sentinel group of older adults ages 55 years and above (n=50) in the Phase 2 study of mRNA-1273 was complete. After reviewing the safety data from the sentinel cohort of older adults, on June 25, the Data and Safety Monitoring Committee of the study recommended Moderna to proceed with enrollment for the remainder of the Phase 2 study. The cohort of older adults (n=300) had been fully enrolled. This Phase 2 placebo-controlled, dose-confirmation study was evaluating the safety, reactogenicity and immunogenicity of two vaccinations of mRNA-1273 given 28 days apart. Each participant is receiving placebo, a 50 μg or a 100 μg dose at both vaccinations.

The Company also announced that the cohorts of older adults (ages 56-70, n=30) and elderly adults (ages 71 and above, n=30) in NIH-led Phase 1 study have completed enrollment. Results were expected to be published once available.