Moderna booster candidates demonstrate robust antibody responses to COVID-19 variants of concern in Phase 2ĭosing started in Phase 1 studies for quadrivalent seasonal flu vaccine candidate (mRNA-1010) and IL-2 mRNA program for autoimmune disorders (mRNA-6231) Moderna COVID-19 Vaccine mRNA-1273: Final blinded analysis of Phase 3 COVE study shows 93% efficacy Efficacy remains durable through six months after second dose