This story is supported by the Pulitzer Center.

It’s been more than three months since COVID-19 vaccines arrived in Chicago, and employees at Heartland Health Centers are working all hours to do something they aren’t set up for: immunizing hundreds of people a day.

Right now, the provider that serves mostly Latino and Black patients vaccinates about 120 people a day inside a large conference room at its Rogers Park clinic on the Far North Side.

But on Monday, Heartland plans on opening its own mass vaccination site at Northeastern Illinois University, and finding enough space and people to run it has been a big lift.

That means hiring 15 extra staffers with just a two-person human resource team, according to Heartland COO Megan Erskine. She’s even jumped in to help.

“I’m talking to medical assistant candidates at 7 o’clock at night and hiring them on the spot,” Erskine said.

Heartland is the type of clinic that serves those who need vaccines the most – people of color hardest hit by COVID-19. But its story helps illustrate why the city has steered more vaccine to some providers, while little or none go to others, according to a WBEZ analysis.

“It’s still a big lift or it’s a pivot for a primary care clinic who serves as a medical home to move to a mass vaccine model,” Erskine said. “It’s kind of like asking your private doctor to do mass vaccines.”

That helps explain the broad disparity in where vaccine doses are distributed throughout Chicago. Heartland has received just over 3,000 doses of vaccine through mid-March. Compare that to the more than 60,000 that have gone to the University of Chicago Medical Center across the city in Hyde Park, a prominent teaching hub that can vaccinate at least 1,000 people a day. Or to the mere 300 doses that went to a small storefront clinic in West Englewood.

The Chicago Department of Public Health controls where the majority of doses flow to providers across the city. Given Mayor Lori Lightfoot’s focus on equity, it might seem unbalanced that Heartland isn’t getting more vaccine. Black and Latino Chicagoans are disproportionately getting sick and dying of the coronavirus.

But since the vaccine rollout began in December, big academic hospitals with large workforces and vast numbers of patients have received the most doses, according to a WBEZ analysis of city data obtained through the Freedom of Information Act. The data is through March 12.

Altogether, four prominent teaching hospitals – U of C, University of Illinois Hospital, Northwestern Memorial Hospital and Rush University Medical Center – received almost 240,000 doses, or almost 30% of the nearly one million doses shipped to providers in Chicago. Each of these hospitals is now receiving more than 5,000 doses a week – up to 10 times what Heartland’s been recently getting.

Many groups of clinics like Heartland and so-called safety net hospitals, which are the backbone of health care for low-income people of color, have received a fraction of the doses that big hospitals have received.

Chicago’s top doctor, Allison Arwady, said the challenges of ramping up vaccination operations on the fly is an obstacle to getting doses to the Chicagoans hardest-hit by the virus – people who tend to live farther away from big medical centers.

“Even when we talked to some of these little providers, some of the storefront providers, some of them are just like, ‘I’m not doing that right now. Come back when … I can potentially have some more capacity to do this,” said Arwady, who leads the Chicago Department of Public Health.

Why more vaccines are going to big hospitals vs. community clinics

Instead of focusing on mass vaccination sites, Arwady told WBEZ she wants to push vaccine mostly through health care providers – big and small – as the city prioritizes equity, given that they’re the ones who know their patients best and can quickly track who should be first in line.

That patient outreach is better, she says, than eager residents fiercely competing online for an appointment. The latter process leaves out many people who aren’t tech-savvy, can’t leave work during the day or don’t have a ride to travel miles from their neighborhood to get a shot.

When it comes to getting more doses, Chicago’s public health department rewards providers for efficiency and equity – in other words, hospitals, clinics, pharmacies and individual physicians who focus on vaccinating residents who have been hardest-hit by COVID-19. That includes seniors and people in neighborhoods with high infection and death rates from the coronavirus.

Giving more vaccine doses to big hospitals is by design, Arwady said. That’s because they’re essentially well-oiled vaccination machines: They have thousands of employees and patients to vaccinate, ultra-cold freezers to store doses and enough money to quickly ramp up to become mass immunization outfits.

Arwady said Northwestern Memorial Hospital in downtown Streeterville, for example, was the city’s No. 2 vaccinator among hospitals for patients over 65.

These large hospitals are hubs for specialists that treat rare diseases, help manage chronic conditions and perform difficult surgeries. But they attract a lot of patients from the suburbs and even across the world, too – in other words, not Chicagoans.

“The small providers are really your sweet spot there,” Arwady said, referring to efforts to vaccinate hard-to-reach communities in the city.

Chicago’s vaccine balancing act

The drawback of small clinics, however, is that they typically don’t have as many patients or resources as big hospitals and health systems, so they can’t vaccinate as many people as quickly.

Here’s where the delicate balancing act of where to direct vaccine doses comes into play. The big hospitals have asked for more doses than they’ve received, Arwady said.

“I’ve had to say ‘no’ to a lot of the big hospitals, who have been some of the loudest in terms of ‘We could be doing more,’” Arwady said.

The city wants to make sure safety net hospitals and clinics get a share of doses, too. But still, the city’s data show these providers are getting far fewer doses compared to the big hospitals.

Loretto Hospital in Austin on the West Side, which has been criticized for vaccinating people who aren’t eligible, has received at least 25,000 doses – less than half what the University of Chicago Medical Center has received.

Other safety net hospitals for low-income patients are in the same situation. St. Bernard Hospital in Englewood on the South Side has received at least 14,000 doses. Chicago Family Health Center, a small group of clinics on the South Side, received just under 3,000 doses. So did PCC Wellness, which has clinics on the West Side and in the suburbs.

But Arwady said that disparity in where doses are going is not entirely the city’s fault. There are pockets of health deserts with few providers – or none at all – to ship doses to. And Arwady emphasized that where doses are shipped isn’t necessarily where people are vaccinated. Many providers have been taking shots to neighborhoods hardest hit by the coronavirus, vaccinating people at parks and inside schools and churches.

Safety nets and clinics that mostly serve low-income Chicagoans aren’t making large requests. Many clinics are requesting small numbers of doses because they’re juggling vaccinations while also treating patients for regular check-ups and sick visits.

Other providers don’t have the resources to scale up like big hospitals do. They also need to use the majority of their vaccine before the city will give them more doses, and they need to report to public health officials who they’re vaccinating.

Some also will be getting separate shipments from the federal government.

But with not enough vaccine yet flowing into Chicago, Arwady said the city has tried to divy up doses to many different types of providers. She also said it’s given some safety net and smaller providers more leeway when it comes to being a little slow on reporting or needing more support.

“We want to support the small ones,” Arwady said. “We want to grow them where they’re able to, and we want to come and fill in sort of all around them and help kind of get this done.”

Getting this done at Heartland has meant figuring out how to handle the vaccine – or “liquid gold,” as Erskine calls it – while keeping up with typical sick visits and routine check ups. They’ve also had to launch a second call center just for vaccination appointments, as the existing one was already overwhelmed with regular patients. And now, they’re hustling to open the new mass vaccination site next week.

“I think I hired seven people in the last 48 hours, so we’re going to be ready to rock n’ roll on Monday,” Erskine said.

Kristen Schorsch covers public health on WBEZ’s government and politics desk. Follow her @kschorsch. Reporter Becky Vevea contributed.