There are more than one million people in Illinois who could be eligible to get a COVID-19 vaccine first, but only a small fraction of them will actually get a shot in the arm before the end of the year.

The federal government could approve a vaccine for emergency use authorization on Dec. 10 and the first doses could be injected by Christmas. But who will get vaccinated first? And how long will the line be?

The short answer: hospital workers.

The long answer is much more complicated.

The state’s vaccine distribution draft plan defines the first priority group as “critical workforce members who provide health care.” The next group includes “staff and residents in long term care facilities” and third is “critical workforce members who provide essential functions of society.” Chicago’s distribution plan is the same, though it also includes anyone over the age of 65.

But the state has yet to define exactly how many people are in each of those categories. And, it’s possible that residents in long-term care facilities will actually get vaccines before all of the health care workers are vaccinated. Repeated requests to the Illinois Department of Public Health and Governor’s Office detailing how many people fall into each of the priority groups went unanswered. In various press conferences, the state has said it is working on a more detailed plan to come.

But here’s some data available so far — nationally, there are 21 million health care workers and 3 million long-term care facility residents, according to the Centers for Disease Control and Prevention. And according to data from the Bureau of Labor Statistics, there are 1.1 million health care workers in Illinois, which includes registered nurses, dentists, health care aides, and even veterinarians.

Illinois Public Health Director Dr. Ngozi Ezike has said the first priority group will include more than just doctors and nurses.

“It will include the sanitation engineers and the people who turn the bed over after a patient has left,” Ezike said at a recent press briefing.

Chicago’s Department of Public Health told WBEZ they estimate 400,000 health care workers in the city that would be eligible for a vaccine.

“We anticipate that we will not receive enough doses initially to cover all healthcare personnel,” said CDPH Medical Director Candice Robinson. “There will be some considerations that hospitals can use to determine which amongst their healthcare personnel should be vaccinated first.”

On Tuesday, Gov. JB Pritzker said Illinois expects to soon receive 109,000 vaccines for the whole state, including allotments for Chicago.

And Chicago’s Public Health Commissioner Dr. Allison Arwady said Tuesday Chicago is expecting to get between 20,000 and 25,000 doses of vaccine in the next two weeks, according to the latest estimate from the federal government.

That would only cover about 5% of the city’s health care workers. But Arwady said the city is anticipating additional allotments “every single week.”

Still, it will take a few months to vaccinate all healthcare workers who want to be. Under emergency use authorization, workers are not required to get vaccinated.

“I am certainly planning to be vaccinated myself,” Arwady said. “But this will be a choice that people will have, particularly early on.”

How will distribution work?

Vaccine distribution will be tightly controlled, according to Josh Michaud, Associate Director of Global Health Policy with the Kaiser Family Foundation. Every dose given is supposed to be tracked and reported to the federal government. Both of the leading vaccine candidates require two doses.

Illinois officials also plan to use the same system it uses to vaccinate children under 18 for getting COVID-19 vaccines to eligible workers. All hospitals, clinics, pharmacies and other organizations that are planning to administer the vaccine will have to register with the Illinois Comprehensive Automated Immunization Registry Exchange, known as I-CARE. Registered organizations will need to be trained specifically on the COVID-19 vaccines and sign the CDC COVID-19 Vaccination Program Provider Agreement.

Who gets the first vaccine shipments could depend on which vaccine the FDA approves. The one from Pfizer and BioNTech is being considered for emergency use authorization on Dec. 10, but it requires ultra-cold storage. If a hospital does not have an ultra cold freezer, it could be more of a logistical challenge. However, Pfizer said its vaccine can be kept in a normal freezer for up to five days. The company also said it will be using special shipping boxes that can be used as temporary storage for up to 15 days with additional dry ice.

The Moderna vaccine will likely be considered for emergency use authorization on Dec. 17. It is potentially easier to distribute because it does not require ultra-cold storage and can be stored for 30 days in a regular refrigerator.

Arwady said Tuesday that Chicago has a warehouse with ultra-cold storage that can hold up to 130,000 doses. While all 37 Chicago hospitals are registered and prepared to distribute vaccines, they don’t all have ultra-cold storage. Arwady said her department is committed to helping ensure even small, safety net hospitals — which offer care to primarily poor and uninsured residents — get early access to the vaccines.

Chicago also launched a website where it will post updates to its vaccination plans as more details become available.

Big pharmacy networks to help vaccinate long-term care residents, employees

It is possible that the second group of people prioritized for a COVID-19 vaccine — those in long-term care facilities — could begin getting vaccinated before everyone in the first group gets offered a shot in the arm.

That’s because the federal government already contracted with Walgreens and CVS Pharmacy to work with nursing homes and other long term care facilities to vaccinate residents.

“The feds will be distributing vaccines directly to CVS, Walgreens, and that would be in parallel to the state system,” Michaud said.

Illinois records indicate there are 1,000 long-term care facilities with room for roughly 100,000 patients across that entire network of homes.

However, according to a WBEZ analysis of data from the Illinois Department of Healthcare and Family Services, there were about 750 licensed long-term care facilities operating in January, with about 73,000 residents. The number of residents has decreased since the pandemic began.

Once the roughly 1.2 million Illinoisans in the two priority groups are offered a COVID-19 vaccine, the details of distribution for who comes next gets far murkier.

That’s because the third category outlined in the latest guidance from the Centers for Disease Control and Prevention is the amorphous “essential workers.” There are an estimated 80 million people across the country who could be classified as essential workers, including grocery store workers, teachers and construction workers. It is not clear how many people there are in each category in Illinois.

Becky Vevea covers city politics for WBEZ. Follow her @beckyvevea.

This story is a part of the Solving for Chicago collaborative effort by newsrooms to cover the workers deemed “essential” during COVID-19 and how the pandemic is reshaping work and employment.

It is a project of the Local Media Foundation with support from the Google News Initiative and the Solutions Journalism Network. The 19partners span print, digital and broadcasting and include WBEZ, WTTW, the Chicago Reader, the Chicago Defender, La Raza, Shaw Media, Block Club Chicago, Borderless Magazine, the South Side Weekly, Injustice Watch, Austin Weekly News, Wednesday Journal, Forest Park Review, Riverside Brookfield Landmark, Windy City Times, the Hyde Park Herald, Inside Publications, Loop North News and Chicago Music Guide.