By CBS 2 Chicago Staff

CHICAGO (CBS) — Illinois COVID-19 cases are climbing just as the city prepares to host tens of thousands of people at Lollapaloooza for the first time in two years.

Grant Park will be rocking with about 100,000 people. Preparations are already underway in Grant Park. Stages are being constructed and equipment is in place, but as cases begin to tick up in Chicago and across the state, some are looking to other cities as a possible harbinger of what is to come.

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“The problem really is we don’t know who’s vaccinated and who’s not,” said Dr. Meeta Shah.

Shah is an emergency room physician at Rush University Medical Center. She said the fact that Lollapalooza is outdoors helps when it comes to the likelihood of COVID transmission, but still, she says it’s hard to know whether unvaccinated people will follow Lolla’s mask requirement.

“If you have folks who are congregating, drinking with their friends, they just feel a little bit more relaxed and then you kind of forget that COVID exists,” she said.

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Chicago isn’t the only major city bringing entertainment back this summer. In June and early July, Las Vegas began seeing a rise in COVID-19 cases and hospitalizations. That rise coincided with some bigtime events. On July 3 there were 35,000 people at Allegiant Stadium for an EDM show. There were Fourth of July parties. And on July 10, Allegiant Stadium was packed with 68,000 people — mostly maskless — rocking out to Garth Brooks. That same night, there were 20,000 inside T-Mobile Arena for a UFC fight.

In the weeks after, there was a COVID whiplash. Clark County’s positivity rate jumped from 6.7% to 14%. Cases and hospitalizations are on the rise too. This week, government officials moved to reinstate masking requirements for some people.

So could Lollapalooza tip Chicago over the edge?

“Any time you have large groups of people getting together, it’s possible,” said Shah.

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Everyone who attends Lollapalooza is required to be vaccinated or have a negative COVID test within 72 hours of attending. Those who are not vaccinated are expected to wear a mask. CBS 2 reached out to Lollapalooza for clarification on how they plan to enforce that and is waiting to hear back.

CBS 2 Chicago Staff