By Marissa Parra

CHICAGO (CBS) — Sunday is the last day for Lollapalooza, but it’s only the beginning of Chicago’s concern over the contagious Delta variant.

This Lollapalooza has been unlike any other between the requirements needed to get through the door, including vaccination or proof of a negative COVID-19 test and the mask rule changing about halfway through the festival to include requirements inside the tents.

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This comes as fears of a super spreader event collide with a rise in cases as the Delta variant spreads.

Festivalgoer Emma Green said she will wear a mask as necessary.

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“With the new Delta variant, you just don’t know like what people might be carrying around, and I’m going to go see my grandma in a couple weeks. I don’t want her to get anything,” Green said.

“Honestly, yeah they did a really good job of making sure we had our vaccine cards ready,” another festival attendee said.

At 10 a.m. Sunday Mayor Lori Lightfoot and Dr. Allison Arwady, commissioner of the Chicago Department of Public Health, will give an update on COVID-19 in Chicago.

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So far, more than half the city has been fully vaccinated, but guidance is shifting to include masking up even for those who are fully vaccinated as breakthrough cases start to creep up.