CHICAGO – In southern Illinois, public health officials struggle to fill coronavirus vaccine appointment slots as the region sits on a three-week supply of doses.

It’s far different in north suburban Lake County, where slots for vaccinations fill up so fast that the region is able to maintain barely four days’ supply.

Four months into Illinois’ mass vaccination program, a Tribune analysis of state and local data found deep imbalances in vaccine supply and demand.

The state for weeks kept sending doses to places where it was a struggle to sign up enough people to get vaccinated, while other areas — such as greater Chicago — scrambled to find enough doses for the flood of people eager to get a shot.

That has led to large disparities in vaccine supply such as those seen comparing southern Illinois and Lake County, where the thin inventory makes it hard to add more appointment slots in clinics or ship more doses to doctors and pharmacists hungry for them.

After the Tribune began asking questions about the imbalance last week, the state announced it would send nearly 50% more first doses to local health departments in the suburbs. That could soon help make it just as easy to get shots near Chicago as it is in many downstate regions.

Still, a tougher battle may loom in places where inventory has climbed and the pace of shots waned. In areas that include southern Illinois, there remain large numbers of residents who are ambivalent, nervous or leery of getting vaccinated.

In southern Illinois’ Jackson County, state data shows just 30% of those age 16 to 64 have gotten a shot. But even after doses were opened up to everybody at least 16 years old, the county’s clinics were able to fill less than 10% of available appointment slots over one four-day stretch.

“The help we need now is to address vaccine confidence and hesitancy issues,” Jackson County’s health administrator, Bart Hagston, said in an email last week.

The disparities have lingered, and hesitancy has revealed itself, amid an increasingly precarious time of the pandemic.

A third surge has begun to take hold in Illinois, pushing case counts higher, with hospitals in some regions filling up so fast they’re sparking new concerns about capacity.

Gov. J.B. Pritzker has appeared reluctant to tighten restrictions, in the hope that vaccinations will douse the latest pandemic uptick. But researchers have said that, for now, the state may be weeks or even months away from getting ahead of the surge.

And health officials have stopped using the one-shot Johnson & Johnson vaccine. Although it wasn’t used as much as the two-shot vaccines from Pfizer and Moderna, it helped supplement the effort, and concern over its safety hasn’t helped efforts to reduce hesitancy.

Uneven vaccinations

The unprecedented mass vaccination process has relied mostly on a public health system starved of funding for years and strained from fighting the yearlong pandemic. Still, in just four months, the effort has gotten at least one shot into the arms of roughly half of all Illinoisans 16 and older.

But the rollout has been uneven as its evolved from inoculating only health care workers and the most fragile residents to the broader population.

The analysis follows earlier Tribune reviews that documented how the state initially strained more than most to ramp up a COVID-19 vaccination program, then made up for the slow start by sending disproportionate amounts of the vaccines to areas outside Chicago that the Illinois Department of Public Health had surmised would be able to get shots into arms more quickly.

Complicating matters has been that the city of Chicago gets its doses directly from the federal government, not through the state health department controlled by Pritzker. The city has been lobbying the state to bolster city supplies, arguing that its doses were being given to many suburbanites who either work in the city or could more readily find appointments there.

At the same time, many Chicago area residents trekked downstate to get shots. Jackson County’s Hagston estimated that, at one point, a tenth of his clinics’ customers were Chicago-area residents who made the long journey to the county’s clinics in Carbondale — a five-hour drive from the Loop.

Others ventured to sites closer to Chicago, such as Bloomington. That led local health officials initially to restrict their county-run clinics to local residents, although secondary providers, such as pharmacies, kept their slots open to people who qualified regardless of their home address.

That vaccine tourism helped mask the geographic imbalance of supply and demand in publicly available data, since the state tracks vaccinations by where recipients live, not where they got their shot.

Still, even the vaccine tourism wasn’t enough to even out the imbalance in the state’s vaccination figures for the 11 designated regions in Illinois’ coronavirus plan.

The Tribune previously found that regions that received a higher number of doses proportionally broke out of the gate early, led by the west-central region, which stretches across 18 counties, from Quincy to Springfield.

By Feb. 25, a month after the state opened vaccinations to all seniors and essential workers, the west-central region led the state with nearly 10% of its residents fully vaccinated. In last place at the time was the region that combines Lake and McHenry counties, at 4%.

Nearly two months later, the west-central region still holds a sizable lead, while regions in the Chicago area are just beginning to catch up.

Inventory disparities

As the vaccination effort got underway, the Pritzker administration pushed doses to places it said could administer them more quickly. Local health departments complained they were largely in the dark about how much vaccine they’d be getting from the IDPH.

But as the imbalance in vaccinations became apparent, the state’s formula evolved. It sent every county at least a certain number of shots, based on population, and publicized those figures online.

IDPH also held back a sizable number of doses it said were needed to target areas of high need or to get shots to particularly vulnerable groups through safety-net hospitals and National Guard clinics across the state. The state has not replied to the Tribune’s request on where those doses have been sent.

IDPH has also asked counties that felt they had enough supply to shift any of their remaining allocations back to the state, to distribute to areas of higher demand.

Still, that wasn’t enough to stop inventory from ballooning in some parts of the state.

One way to look at the situation is to measure the average number of doses on hand each day, compared to the average daily number of residents getting vaccinated. That formula shows three regions — West-Central, Metro East and South — have enough doses to vaccinate their residents, at their current paces, for more than three weeks.

Near Chicago, inventory levels are far smaller. IDPH doesn’t track the city of Chicago’s inventory, but for the four regions that encompass the suburbs, supply levels have lingered at 10 days or less.

The shortest supply can be found in the region that combines Lake and McHenry counties, which had on hand a supply good for barely four days’ worth of vaccinations.

Mark Pfister, director of Lake County’s health department, told the Tribune last week that his Lake County department has no trouble still filling up all appointment slots at clinics it runs. It also cannot keep up with all of the physicians and pharmacists vying for the doses provided by IDPH.

“I can tell you that we have many providers that are not happy with us,” Pfister said last week.

High demand in Chicago area

One reason inventory levels are so low is because demand near Chicago remains so high.

While other parts of the state have seen the number of daily vaccinations stagnate — even drop — over the past month, the Chicago area has seen a surge in the number of residents getting vaccinated.

In the region that combines DuPage and Kane counties, roughly 12 shots a day are being administered for every 1,000 residents, double the pace of two months ago.

Compare that to the South region, where the pace is roughly four shots a day per 1,000 residents, or about half what it was a month ago.

The faster pace of vaccinations in the Chicago area has led to a much higher percentage of residents who have received one shot of the two-dose Pfizer and Moderna vaccines.

If those partial vaccinations are included, regions near Chicago are on par, if not leading, the rest of the state in vaccinations.

The region covering DuPage and Kane counties now tops the state in the percentage of those 65 and over who’ve gotten at least one shot, at 83%. It also tops the state in the percentage of those 16 to 64 who’ve gotten at least one shot, at 43%.

But the data reveals the other side of those trends: the regions struggling to put shots into arms. The South region has just 23% of its residents ages 16-64 who’ve gotten at least one shot.

Shifting doses amid hesitancy

One of the largest counties in the region is Jackson County, home of the Carbondale campus of Southern Illinois University. The National Guard helps the county run two vaccination clinics.

One of the county’s busier days recently was when it opened eligibility to anyone 16 and older, county records show. On that day, March 29, it was able to fill nearly 80% of its 1,700 daily appointment slots.

But the next day, it filled less than 30% of slots. The rest of the week, for roughly every shot given, there was another slot left unfilled.

The next week was even worse. On four days, less than 10% of available appointments were filled. On one day just 5% of slots were taken. And that was after the county reduced the number of available appointments each day to just 1,480. Just 57 people showed up at one clinic that day, and 22 at the other.

Hani Mahmassani, who directs Northwestern University’s Transportation Center and has been commissioned by the National Science Foundation to help study the rollout, said open slots downstate are evidence of vaccine hesitancy, as well as the loss of traffic from Chicago-area residents who are now able to find shots closer to home.

That hesitancy has been seen in other parts of the country, particularly more rural ones that lean Republican, fitting the profile of many counties outside the Chicago area. Polls last week by Monmouth University and Quinnipiac University found nearly half of Republicans plan to avoid getting vaccinated, compared with less than a tenth of Democrats.

The Pritzker administration has said it has a plan in place to address the hesitancy, that includes using federal money to push ads into areas where the data shows have higher vulnerability and lower uptake.

“At the start of the vaccine rollout the state tested messages to find the most effective one and surveyed the population to gauge their hesitancy. We built a campaign that could be adjusted as we learned more about who needed to be targeted,” Pritzker spokeswoman Jordan Abudayyeh wrote in an email last week.

At the same time, the state this week abandoned automatic dose disbursements to counties, based on their populations, for a formula that looks at inventory levels and needs.

That new formula means a massive influx of doses into the four suburban regions near Chicago. To put it in context, the Pritzker administration announced last week that IDPH would be making a one-time disbursement of 50,000 first doses (and, later, 50,000 second doses) to Chicago to help with its shortfall.

Suburban Chicago regions will be getting nearly 51,000 additional first doses this week under the new formula, and that doesn’t count weeks going forward when the new formula remains in effect.

Chicago-area health officials told the Tribune last week they were eager for more shots.

“We don’t have any trouble filling appointments or finding arms,” said Cindy Jackson, Will County’s vaccination director, in an email.