The FDA has issued an Emergency Use Authorization (EUA) for an adjuvanted protein subunit COVID-19 vaccine manufactured by Novavax. The vaccine is indicated for use as a two-dose primary series to prevent COVID-19 in adults; it is not authorized for use in children or as a booster dose. Three other COVID-19 vaccines are available in the US for primary immunization of adults; the mRNA vaccines manufactured by Pfizer/BioNTech (Comirnaty) and Moderna (Spikevax) are FDA-licensed for this indication, and the adenovirus-based vaccine manufactured by Johnson & Johnson (Janssen) is available under an EUA for use in adults who are unable or unwilling to receive another COVID-19 vaccine.