In December 2020, two COVID-19 vaccines were granted Emergency Use Authorization (EUA) by FDA. Produced by Pfizer/BioNTech and Moderna, both vaccines use the same technology (mRNA) and are highly effective at preventing COVID-19 infection. In February 2021, a COVID-19 vaccine developed by Janssen Biotech, Inc. was granted an EUA by FDA. A comparison of key details for each vaccine can be found below. This list is not exhaustive. For further details, see the FDA EUA document for Pfizer/BioNTech, Moderna, and Janssen. Note: head-to-head COVID-19 vaccine studies have not been conducted. Therefore, direct vaccine efficacy comparisons are not possible at this time.