The new guidelines come as thousands gathered outside the White House during President Trump's speech Thursday night were seen sitting and standing close together and not wearing masks.
"The CDC determines exposure to COVID as more than 15 minutes within 6 feet apart," said Dr. Sindhu Aderson, with Northwestern Medicine.
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Because the Trump speech was much longer than 15 minutes, Dr. Aderson said everyone who attended has a huge risk of getting COVID.
Chicago's Fraternal Order of Police President John Catanzara was there.
"Me personally, I'm not necessarily concerned about it," he said.
But Eli Musser says everyone should be concerned. Before contracting COVID-19 five months ago , he was a perfectly healthy musician with a clear voice. Now, the 42-year-old can barely talk, one of the many lingering health effects.
"I have not been able to work, I'm too dizzy, weak and a hard time breathing," Musser said.
Musser said no one should put themselves in a position where they could be exposed or expose others. In addition to large gatherings at the Republican convention this week, the CDC rolled back testing guidelines saying only people with symptoms need to get tested - a move many doctors are against.
"It is a danger because we are seeing a lot of these secondary infections from people who don't know they are positive," Dr. Aderson said.
In the meantime, organizations representing public health departments around the country sent a letter to the CDC urging the agency to pull its new guidance on testing.
Gov. JB Pritzker said Illinois will continue its robust testing.
"I know the president doesn't believe in science and would like to ignore this pandemic, but it's the job of our medical institutions to uphold science and provide straightforward public health guidance, not bow to political pressure," Pritzker said in a written statement.