The massive Lollapalooza music festival kicked off Thursday in Chicago, drawing tens of thousands of revelers to the city’s downtown and renewing worries about the coronavirus spreading in the tightly packed crowds.
The four-day festival is expected to be one of the largest gatherings in the United States since the pandemic began. About 100,000 people are set to attend each day of the event, which is being held at Chicago's Grant Park and will feature 170 bands on eight stages.
Organizers say those attending will need to show proof of full vaccination or a negative coronavirus test if unvaccinated. The unvaccinated must also wear a face mask throughout the site.
But there are still widespread concerns that the highly infectious delta variant may show up at large live events this summer.
"We want you to have fun, but please keep all rules and requirements in mind and continue to #ProtectChicago," Chicago Mayor Lori Lightfoot tweeted.
Summer music festivals, silenced by the pandemic last year, have returned as vaccines have become widely available and local governments have eased public health restrictions. But the delta variant, responsible for infection surges in all 50 states, has raised fears that the gatherings could become superspreader events.
Even well-ventilated, outdoor sites pose risks, say infectious-disease experts, who say festivalgoers are likely to have a hard time keeping the necessary physical distance when crowds are packed in, and everyone is dancing, singing, sweating, and drinking.
There is also a risk of increased transmission at chokepoints such as entrances, bathroom lines and at the space nearest to the stage where crowds tend to pack in the tightest, they say.