What are mRNA vaccines?

Both the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 Vaccine are lipid nanoparticle-formulated, nucleoside-modified mRNA vaccines encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19. The 2023–2024 formula targets the Omicron XBB.1.5 sublineage of the spike protein. Visit this CDC website for more details about how mRNA vaccines work: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/how-they-work.html.