On May 31, 2025, Moderna announced that the U.S. Food and Drug Administration (FDA) had approved mNEXSPIKE® (mRNA-1283), a new vaccine against COVID-19, for use in all adults 65 and older, as well as individuals aged 12-64 years with at least one or more underlying risk factor as defined by the Centers for Disease Control and Prevention (CDC).

The FDA’s approval of mNEXSPIKE is based on results from a randomized, observer-blind, active-controlled Phase 3 clinical trial (ClinicalTrials.gov Identifier: NCT05815498), which enrolled approximately 11,400 participants aged 12 years and older. The primary efficacy objective in this study was to demonstrate the non-inferior vaccine efficacy against COVID-19 starting 14 days after mNEXSPIKE compared to that after the comparator vaccine, mRNA-1273 (Spikevax®), Moderna’s original COVID-19 vaccine. Participants received either a 10 μg dose of mRNA-1283 or a 50 μg dose of mRNA-1273. mRNA-1283 showed a 9.3% higher relative vaccine efficacy (rVE) compared to mRNA-1273 in individuals aged 12 years and older, and in a descriptive sub-group analysis, a 13.5% higher rVE in adults aged 65 and older.

In the Phase 3 trial, mRNA-1283 was found to have a similar safety profile to mRNA-1273, with fewer local reactions and comparable systemic reactions. The most commonly solicited side effects were injection site pain, fatigue, headache and myalgia.

Moderna expects to have mNEXSPIKE available for eligible populations in the U.S. for the 2025-2026 respiratory virus season, alongside Spikevax and mRESVIA®, the Company’s approved respiratory syncytial virus (RSV) vaccine.

mRNA-1283 is under review with regulators in multiple markets around the world.