FDA issued the second emergency use authorization (EUA) for a vaccine for the prevention of COVID-19. The EUA allows the Moderna COVID-19 Vaccine to be distributed in the United States for use in individuals 18 years of age and older. The Moderna vaccine is administered as a series of two doses, one month apart. The available safety data to support the EUA include an analysis of 28,207 of the participants enrolled in an ongoing randomized, placebo-controlled study. The vaccine was 94.1% effective in preventing COVID-19 disease among these clinical trial participants with 11 COVID-19 cases in the vaccine group and 185 in the placebo group. At this time, data are not available to make a determination about how long the vaccine will provide protection, nor is there evidence that the vaccine prevents transmission of SARS-CoV-2 from person to person.