As states prepare COVID-19 inoculations for a wider swath of the population, researchers who have been mapping potential vaccine distribution sites found that, in dozens of counties across the country, Black residents are more likely than white residents to live farther away from a site.

Long drives to vaccination sites may keep people from getting the vaccine, and could widen the already-significant health disparities between Black and white Americans, wrote the researchers, from the University of Pittsburgh and the West Health Policy Center.

Researchers hope health departments around the country will use the mapping project to pinpoint under-served areas of their communities and open more convenient facilities like mobile clinics or mass vaccination sites at gyms and stadiums. Many counties, including in the Philadelphia region, have already begun to open such sites.

“The idea is not to say Black Americans will have less access to the vaccine. It’s that, unless you do something, they’ll have less access to the vaccine,” said Sean Dickson, the director of health policy at West Health.

The analysis mapped 68,128 sites across the country that would likely hand out vaccines: hospitals, federally qualified health centers, rural health clinics, and community pharmacies that have already hosted immunizations, like the annual flu shot. Researchers found that 25% of counties in the country had three or fewer potential vaccine facilities, and that rural states like Montana, South Dakota, and Wyoming had the longest average driving distance to a potential facility.

But disparities aren’t limited to rural areas.

“In urban areas, we found particularly large disparities in Atlanta, New Orleans, and some of the large Texas metro areas, Dallas-Fort Worth and Houston,” said Inmaculada Hernandez, an assistant professor of pharmacy and therapeutics at the University of Pittsburgh and one of the study’s authors.

In those areas, Black residents were more likely to have to drive more than a mile to the closest vaccine facility than white residents. And in 90 counties in the country -- including York County in Pennsylvania -- Black residents had a significantly higher likelihood of having to drive 10 miles or more to a vaccination site.

Hernandez said the mapping project has implications beyond the distribution of the COVID-19 vaccine, showing how many Americans lack easy access to health-care facilities.

The study also shows how health disparities manifest in different ways around the country, Hernandez said. Some counties had very few health-care facilities and long driving distances to reach them; in other counties, there were shorter driving distances to vaccine distribution sites, but not enough facilities to handle the number of people who need to be vaccinated.

And then there were counties where potential vaccine access varied greatly by race.

“The COVID-19 pandemic has demonstrated and accelerated the existing fault lines in race and health care,” Dickson said. “The disparities we’ve outlined here are only potential disparities. They’re disparities if we choose not to act on them.”