“COVID-19 remains a serious public health threat, with more than 47,000 Americans dying from the virus last year alone,” said Stéphane Bancel, chief executive of Moderna, as the company announced that the U.S. Food and Drug Administration had approved its new vaccine mNEXSPIKE (mRNA-1283). The release was dated May 31, 2025.
The vaccine is the company’s third FDA-approved product. It is cleared for all adults 65 and older, and for people aged 12 to 64 who have at least one underlying condition that puts them at high risk of severe COVID-19. Bancel called it “an important new tool to help protect people at high risk of severe disease.”
What the trial showed
The approval rests on a Phase 3 study that was randomized, observer-blind and active-controlled. It enrolled approximately 11,400 participants aged 12 and older. Moderna set out to show that mNEXSPIKE protected against COVID-19, starting 14 days after the shot, at least as well as its original vaccine, Spikevax (mRNA-1273).
Volunteers received either a 10 μg dose of mRNA-1283 or a 50 μg dose of mRNA-1273. The new vaccine came out ahead: relative vaccine efficacy was 9.3% higher among everyone 12 and older. In a descriptive sub-group analysis of adults 65 and older, it was 13.5% higher.
Safety looked similar. The company said mRNA-1283 produced fewer local reactions than Spikevax and about the same level of systemic ones. The most commonly reported effects were pain at the injection site, fatigue, headache and muscle pain.
Who should be careful
The prescribing information carries the usual warnings for mRNA COVID-19 vaccines. Anyone who has had a severe allergic reaction to an earlier Moderna COVID-19 shot, or to an ingredient in it, should not receive mNEXSPIKE. Such reactions are very rare and usually start within minutes to an hour, so clinics may ask people to stay briefly after the injection.
Myocarditis and pericarditis, inflammation of the heart muscle and of the lining around the heart, have occurred in some people after mRNA COVID-19 vaccines, most often in males aged 12 to 24. Symptoms such as a fast-beating, fluttering or pounding heart need medical attention right away, especially in the two weeks after a dose.
Patients should tell the person vaccinating them about bleeding disorders, blood thinners, an immune system that is weakened or affected by medication, pregnancy or plans for it, and any history of fainting with injections.
Availability
Moderna expects mNEXSPIKE to reach eligible people in the U.S. for the 2025-2026 respiratory virus season, alongside Spikevax and mRESVIA, its RSV vaccine. Regulators in several other markets are also reviewing mRNA-1283.
Anyone unsure whether they qualify should talk to their doctor.
