How does a mass vaccination site work? Here’s a look inside one at a former K-Mart in Des Plaines.

Illinois has 18 mass vaccination sites running across the state. To see how they work, the Tribune visited a new site set up inside a vacant K-Mart in Des Plaines .

The vaccination site, on Oakton Street, opened Thursday, along with a site at the convention center in Quincy that together can give shots to up to 4,000 people a day once at full capacity.

Illinois passed a notable benchmark in its vaccination effort Friday, with more than 1 million people fully vaccinated — 8% of the state’s overall population.

Residents at the Des Plaines site were administered the Johnson & Johnson vaccine.