The Moderna COVID‑19 vaccine (pINN: elasomeran), codenamed mRNA-1273 and sold under the brand name Spikevax, is a COVID-19 vaccine developed by Moderna, the United States National Institute of Allergy and Infectious Diseases (NIAID) and the Biomedical Advanced Research and Development Authority (BARDA). It is authorized for use in people aged twelve years and older in some jurisdictions and for people eighteen years and older in other jurisdictions to provide protection against COVID-19 which is caused by infection by the SARS-CoV-2 virus. It is designed to be administered as two or three 0.5 mL doses given by intramuscular injection at an interval of at least 28 days apart.

It is an RNA vaccine composed of nucleoside-modified mRNA (modRNA) encoding a spike protein of SARS-CoV-2, which is encapsulated in lipid nanoparticles.

It is authorized for use at some level in many countries.

On 15 March 2021, Moderna's second COVID‑19 vaccine (mRNA-1283) started phase I clinical trials. This vaccine candidate can potentially be kept in refrigerators instead of freezers, making distributions easier especially in developing countries.