The District of Columbia has “a high social vulnerability” when it comes to COVID-19, but the city did not qualify for a mass vaccination site because it isn’t part of a larger state, acting director of the Federal Emergency Management Agency Bob Fitton told reporters on Friday.

FEMA currently has 21 mass vaccination sites scattered across the country to help quickly get shots in arms. These sites, which were set up after the Biden administration took office, can inoculate thousands of people per day. Many of the sites are near cities with high minority populations and many people who are particularly vulnerable to COVID-19.

Fitton hopped on a call with reporters Friday to explain how the agency is ensuring equity at these mass vaccination sites and said it’s important these sites are in underserved areas because COVID-19 has disproportionately impacted minorities. The nation’s capital is nearly 50 percent Black, and Black people have experienced a high percentage of COVID-19 hospitalizations and deaths. Still, they are getting vaccinated at a much slower rate than white people in the District.

FEMA determined the location of mass vaccination sites based on population, Fitton said, starting with the most populous state and going down the line. Then in each state, FEMA picked an area with high coronavirus vulnerability to set up the vaccination sites.