Spikevax is a vaccine developed by Moderna to protect against COVID-19. It is an mRNA vaccine that contains instructions for producing a protein from the original strain of SARS-CoV-2, the virus that causes COVID-19. The vaccine is available in different formulations, including a bivalent vaccine for the original and Omicron BA.1 strains, a monovalent vaccine for the Omicron XBB.1.5 subvariant, and an updated vaccine that contains spike proteins for the XBB.1.5 sublineage of SARS-CoV-2. Spikevax is approved for use in individuals 6 months of age and older. The vaccine is administered through injection and may cause some common side effects such as injection site pain, headache, fatigue, myalgia, and chills.