Several COVID-19 vaccines are being studied in trials around the country. Once the Food and Drug Administration authorizes a vaccine for use, health leaders must decide which groups of people get to receive the vaccine first.

Thomas Hansler, 54, receives a COVID-19 vaccination from Yaquelin De La Cruz at the Research Centers of America in Hollywood, Florida on August 13, 2020. (Photo by CHANDAN KHANNA / AFP) (Photo by CHANDAN KHANNA/AFP via Getty Images)