mRNA1273

mRNA-1273 is an mRNA vaccine developed by Moderna, in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID), part of the U.S. National Institutes of Health. The vaccine uses lipid nanoparticles to deliver messenger RNA that encodes the prefusion-stabilized full-length spike glycoprotein of SARS-CoV-2. After the mRNA is taken up by cells, the spike protein is produced and triggers an immune response that includes neutralizing antibodies and T-cell activation.

In clinical development, mRNA-1273 demonstrated strong immune responses and efficacy against symptomatic COVID-19 in phase 3 trials. It received Emergency Use Authorization from the U.S. Food and Drug Administration in December 2020 and later obtained full approval for adults in 2022. It has been widely used in national vaccination programs and has supported booster campaigns as new variants emerged. The primary vaccination series consists of two 100 microgram doses given 28 days apart; booster doses at lower amounts (for example, 50 micrograms) have been authorized to enhance protection, particularly against circulating variants.

Safety data indicate that most adverse reactions are mild to moderate and transient, such as pain at the injection site, fatigue, headache, myalgia, fever, and chills. Serious adverse events are rare; rare cases of myocarditis and pericarditis have been reported, especially in younger individuals after the second dose. Storage requirements vary by formulation and regulatory guidance, with the vaccine shipped frozen and allowable refrigeration and thawing periods specified by manufacturers and regulators.

Originally marketed as Spikevax, mRNA-1273 is part of the broader class of mRNA vaccines and has played a significant role in global COVID-19 vaccination efforts.