On Aug. 13, 2021, Moderna announced that the Food and Drug Administration (FDA) had approved an update to the emergency use authorization for the Moderna COVID-19 vaccine (mRNA-1273) to include a third dose for immunocompromised individuals 18 years of age or older in the U.S. who had undergone solid organ transplantation, or who were diagnosed with conditions that were considered to have an equivalent level of immunocompromise.