According to the standards set by the US Food and Drug Administration (FDA), an EUA can be granted when the known and potential benefits outweigh the known and potential risks of the drug being considered, and once sufficient efficacy and safety data from phase 3 trials is available. Notably, this cannot be done based on merely phase 1 and phase 2 trial results. The minimum efficacy bar set by the FDA for a COVID-19 vaccine is 50% - and this must be attained after the vaccine has been studied in over 3,000 participants - who are all to be tracked and monitored for any adverse event for at least one month post the administration.