For FDA emergency use authorization, the known benefits of the COVID-19 vaccine must outweigh the known risks. The COVID-19 vaccines have been studied in large clinical trials where over 14,000 individuals received the vaccine. Most people experienced some pain at the site of the injection, and after the vaccination some people experience a short period of flu-like symptoms (fatigue, headache, fever). In addition to the FDA, a group of experts in vaccine safety have reviewed the data from clinical trials. The CDC will also closely monitor the safety of the COVID-19 vaccine.