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 2024–2025 formula targets the Omicron variant KP.2 sublineage of the spike protein.  Visit this CDC website for more details about how mRNA vaccines work: www.cdc.gov/covid/vaccines/how-they-work.html.