By Chris Tye

CHICAGO (CBS) — With so many of these rules relaxing, there’s one big glaring concern left for seasoned experts of infectious disease.

Variants.

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Those strains could kick case counts back up.

CBS 2’s Chris Tye reported Tuesday on how experts are framing this as one of the last big hurdles Illinois needs to clear. Experts said there will be outbreaks of these variants. Illinois is about middle of 50-state pack in variant cases.

“I am super optimistic,” said the University of Chicago’s Dr. Emily Landon.

But in a recent conversation Landon, she added a warning.

“There is the risk of these new variants somewhere on the horizon,” Landon said.

So far, two variants are known to have made their way into Illinois. Nearly 70 cases of the so-called UK variant, or B.1.1.7, have emerged since late last year in Illinois. Most cases are in Cook, Champaign, Lake, and Kane County. As of Tuesday morning, there were 67 cases reported.

The other is the so-called South African variant, or B.1.351. Its footprint is smaller in Illinois. There’s just one Illinois case in the western Illinois county of Rock Island.

“We were very concerned that the variant was here,” said Janet Hill of the Rock Island Health Department.

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Rock Island sits across the river from Iowa, where rules were more lax and case counts far higher. But the patient who contracted the strain hadn’t left the state in weeks, but did have one out-of-state visitor.

“We know it is more contagious and it could have been worse,” said Hill. “And if it were a different point in the pandemic, it possibly could have been worse.”

In the end they contained the variant. That was crucial because these variants spread more quickly than most COVID-19 cases. Current vaccines appear to work against them. The Rock Island patient is doing OK.

UK Doctors said the UK variant possibly more deadly than other more common strains.

“We did brace for a surge, and we didn’t have this thankfully,” Hill said.

But states like Florida, Michigan, and California have seen surges, which experts said are all but inevitable.

“I hope Chicago and Illinois is not one of those places,” Landon added.

Rock Island had a unique case, but the same messaging and practices as every other part of the state: Social distance, wash hands and wear a mask.

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That helped to contain it.