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You may be uncertain about what the COVID-19 vaccine rollout means for you.

We’ll be answering questions about when and where people are going to get vaccinated and how the distribution plans for the state, Cook County and Chicago will impact you. We’ll ask dig into some of the science behind the vaccine and explain how it works.

How many doses of the vaccine have been administered in Illinois?

Chicago is posting daily vaccination tallies on a web page dedicated to the rollout. (The page lags a few days, and some data only includes tallies of Chicago residents.)

Both the state of Illinois and the city of Chicago get weekly shipments of the vaccine. Data showing how many doses have been shipped from each company, Moderna,Pfizer and Johnson & Johnson, is updated by the CDC weekly.

Who is allowed to get a COVID-19 vaccine right now?

As of April 12, all Illinois residents 16 and older are eligible to get vaccinated. The state’s adult population (18 and older) is roughly 9.8 million. Chicagoans can get vaccinated outside the city starting April 12, but city leaders are waiting until April 19 to open up city vaccination sites to everyone 16 and older.

Where will I get a vaccine?

WBEZ created a guide with helpful links to places where COVID-19 vaccines are available.

Think about where you’ve gotten a flu shot in the past. A local pharmacy, a community clinic, your doctor’s office, or maybe even your workplace. Those same places may have COVID-19 vaccines.

Broadly, hospitals, federally-qualified health centers, big pharmacies (e.g. Walgreens, CVS), small independent pharmacies, and even grocery stores that have pharmacies, like Mariano’s and Jewel-Osco, are all authorized to give vaccines.

Employers may also be able to get their staff access to vaccines by contacting their local public health department. In most places, there is no on-site registration — you must have an appointment.

Can I register in advance so I know when it’s my turn to get vaccinated?

Yes. Chicagoans can sign up for additional information at ChiCOVIDCoach. People who are eligible can also join the waitlist to be notified when there are available appointments through Zocdoc, the city’s scheduling partner.

Suburban Cook County residents can register here. Lake County has a registration form here. Will County residents can register here. Kane County has a form to sign up for vaccine updates. DuPage County also has an information sign up. McHenry County allows residents to sign up to receive updates here.

Is the vaccine free?

To you, yes, the vaccine itself is supposed to be free. If you get it from a city- or state-operated vaccination site, like at a mass vaccination event, it should be at no cost to you. But medical professionals in other settings may be able to charge an administration fee for the shot. Vaccine providers are supposed to be able to get that cost reimbursed with the patient’s private or public insurance.

Under Operation Warp Speed, the federal government paid several companies not only to develop these vaccines, but those agreements also included the number of doses that would be manufactured and dedicated to the U.S. versus other countries. But officials have repeatedly asserted that nobody should have to pay for a shot out-of-pocket.

Do I have to get the COVID-19 vaccine?

No. There is no state or federal or city requirement that you get vaccinated. Because both vaccines are still under emergency use authorization, they cannot be mandated. But if you do not take it when available to you, experts say you risk getting the virus and spreading it to others.

Which vaccines have been authorized so far?

The two-dose Pfizer, Moderna and single-dose Johnson & Johnson vaccines are all authorized for emergency use in the United States. 

However, on April 13, Illinois and many other states suspended their use of the Johnson & Johnson single-dose vaccine as federal regulators explore possible connections to rare cases of blood clots that occurred in 6 women soon after they received the shot.

If I get the vaccine, will I be protected from COVID-19 right away?

No. You’ll need two shots, and similar to the flu vaccine, experts say it can still take a few weeks for the vaccine to work after the second shot. And, getting vaccinated doesn’t mean you’ll be 100% protected, just like when you get the flu shot. Everyone is being advised to continue to maintain social distancing and wear masks for some time.

If I have already contracted COVID-19, can I skip the vaccine?

No. Experts say nearly everyone should still get vaccinated. Scientists are still studying how much immunity is conferred from natural infection and how long protective antibodies might last. Though rare, it is possible to get infected with COVID-19 twice.

The currently authorized vaccines also protect against new variants that are circulating. It’s not clear whether getting infected from COVID-19 would confer protection against variants. It’s worth noting that if you’ve had COVID-19 recently and were treated with monoclonal antibodies or convalescent plasma, the Centers for Disease Control and Prevention recommends waiting 90 days before getting a COVID-19 vaccine.

If someone is vaccinated, can they still catch COVID-19?

Yes, but it’s rare. During the trials for the three vaccines currently authorized by the FDA, a very small percentage of people who got the vaccine did get mild cases of COVID-19. However, they were all 100% effective at preventing hospitalization and death.

Early data show the vaccines do prevent people from spreading COVID-19, as well. Scientists are still studying the data as more people get vaccinated. As more people get vaccinated, the virus has less chance to spread and mutate, which is key to the pandemic ending and returning life to a new normal. 

How do we know this vaccine is safe?

All medicines, including vaccines, undergo rigorous phased trials before they’re given to the general public. The COVID-19 vaccine has been developed and approved quickly because this is an emergency. That doesn’t mean scientists cut corners.

This is what it takes:

• Pre-clinical trials see if a vaccine works in animal models, like monkeys, which have a physiology similar to humans.

• Phase I trials test if a vaccine is safe on a small group of participants. Scientists see if those people develop antibodies, which help fight off illness.

• Phase II trials determine which dose is most effective for generating antibodies while remaining tolerable for patients.

• Phase III trials, or randomized control trials, are what you’ve heard about in the news. They take a huge number of participants (the Pfizer trial had more than 40,000) and divide them into two groups. One group gets the vaccine and the other group gets a placebo, or a fake. Because it’s unethical to expose people to COVID-19, researchers waited for participants to get sick out in the world before giving them the test dose. Then they compared the number of COVID-19 cases between the two groups.

In the Pfizer study, the vast majority of the participants who developed COVID-19 were in the placebo group, a statistically significant number that shows the vaccine works. (That’s where the 90% effective figure comes from.) It’s worth nothing that’s astoundingly high – nobody expected the COVID-19 vaccine to be this effective.

The Food and Drug Administration set its benchmark at about 50% effectiveness.

Are there side-effects?

That’s an imprecise term. If you’ve ever felt flu-like after getting a flu shot, that actually shows a vaccine is working.

Vaccines activate your immune system, and your body needs to get a little sick to develop antibodies. Headaches, fevers, aches and pains are just signs our body is responding. So while you may experience similar symptoms after getting a COVID-19 vaccination, it’s absolutely nothing to fear.

I’ve heard the Pfizer and Moderna vaccines are ‘mRNA’ vaccines. What are those?

mRNA vaccines are the most streamlined vaccination method we’ve come up with so far. Their simplicity is brilliant, but the speed at which we’ve developed them is thanks to decades of foundational research on coronaviruses following the SARS and MERS outbreaks.

To understand how mRNA vaccines work, you have to first know the difference between DNA and mRNA, or messenger RNA.

Georgetown Microbiologist Julie Fischer explained it this way: DNA is like a master blueprint that never, ever leaves the wall of the drafthouse, while mRNA is the copy taken to a construction site and thrown away. mRNA has a thankless job. Our cells read this genetic information and then shred it to bits.

mRNA with the genetic instructions to COVID-19’s spike proteins, which it uses to latch onto and infect our cells, is the key to the Moderna and Pfizer vaccines and pretty much the Death Star plans for COVID-19. But to prevent our murderous enzymes from tearing the vaccine apart, both companies developed a fatty, lipid shell to protect it once injected into the body.

Once injected, the lipid shells fuse to our cells and release the mRNA into their cytoplasm. Our cells read the instructions and begin producing the COVID-19 spike proteins. The mRNA from the vaccine is destroyed.

The spikes will then grow and break off from our vaccinated cells. Immune cells, called helper t-cells and antigen presenting cells, which function at the hall monitor of the body, sound the alarm on the foreign objects, collecting and presenting them to other immune cells. T-cells, the enforcers, learn to destroy them. B-cells learn to make antibodies, which neutralize the spike proteins.

What makes the mRNA vaccine exciting?

mRNA vaccines are a brand new technology decades in the making that has distinct advantages over traditional production methods — like speed.

These new vaccines can be produced at a much faster rate because nothing is being grown. Scientists instead synthesize molecular instructions for our cells to make COVID-19’s distinctive spike protein, which our body’s immune system creates antibodies for and destroys, protecting us against the virus.

Vaccines that use attenuated, or weakened, versions of a virus, like the flu vaccine have to be grown in cells or eggs. There are painstaking, laborious steps to creating these vaccines, production is slow by comparison and it is harder to produce at scale.

None of the COVID-19 vaccines awaiting Food and Drug Administration approval utilize this method. Pfizer and Moderna both made mRNA vaccines, while AstraZeneca and Johnson & Johnson developed what are called recombinant vaccines, which disguise a harmless common cold virus as COVID-19 to train our immune system.

All methods ultimately achieve the same goal of immunity, but these new technologies will likely change the future of vaccine production and development.

Vivian McCall is an intern at WBEZ. Becky Vevea covers City Hall. Follow them @vivianmccall @beckyvevea.