CHICAGO (CBS) — “Sign, sign, everywhere a sign”; those are the lyrics to a 70’s song that seem very relevant today.

COVID dos and don’ts are plastered everywhere. How do you know which ones are current and relevant? CBS 2 Morning Insider Tim McNicholas asks an expert.

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“Stand six feet apart,” “masks required,” “temperature checks will be taken.” Basically, if a business has a sign, follow it.

“Any private business is able to mandate a mask, just like they’re able to tell you they’re not going to serve you or let you in if you don’t have shoes,” said Dr. Emily Landon, an infectious disease expert at University of Chicago.

She said, even as the state prepares to fully reopen, some businesses are keeping COVID rules in place to protect employees and customers who might still be at risk.

But regardless of whether a business enforces mask wearing for vaccinated people, Landon said, “individuals who are unvaccinated should be wearing masks in inside spaces.”

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Things get more complicated when it comes to businesses that don’t require everyone to follow the same rules.

“There aren’t a lot of great systems in place for ensuring that it’s only the vaccinated people who are unmasked. We’re largely using an honor system,” Landon said.

Landon said unvaccinated individuals can be at high risk for getting COVID, if there are other unvaccinated people not wearing masks or following social distancing rules.

But regardless of whether you’re vaccinated or not, Landon said, “You should go ahead and wear a mask anytime you want, wherever you want.”

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As for the future of mask wearing? Landon said she expects some places like hospitals and public transportation to enforce mask-wearing long-term.

Tim McNicholas