By Marissa Parra

CHICAGO (CBS) — Health officials Friday announced the first case in Illinois of the more contagious COVID-19 variant first identified in the United Kingdom.

The case was identified by the Northwestern University Feinberg School of Medicine. This new strain does not cause more severe symptoms, but it is more easily spread, officials say. The strain was first confirmed in the UK in September and is so contagious that within just three months, it was the most common strain in the UK despite the lockdown.

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Data suggest current vaccines will be effective and safe in providing protection against the variant.

“This news isn’t surprising and doesn’t change our guidance around COVID-19. We must double down on the recommended safety strategies we know help stop the spread of this virus,” said Chicago Health Commissioner Dr. Allison Arwady.

While the new strain, known as the B117 variant, was detected Friday in Chicagoland, it has actually been here longer, a doctor told CBS 2’s Marissa Parra. Dr. Egon Ozer, who works with infectious diseases at Northwestern University, said he has been analyzing random samples of the virus since May and found the new strain in a sample from late December.

Over the last several weeks, Ozer tests roughly 200 random COVID-19 samples. He said finding the new strain was not a matter of if but when.

“We were expecting it to show up here at some point,” he said. “It would have been very interesting if it had not.”

The person infected had recently traveled to the United Kingdom and the Middle East, officials said.  Tracers have begun looking at the patient’s contacts. Officials did not say where the person lives, but the Chicago Department of Public Health is investigating the case, which would indicate the patient lives in the city.

The COVID-19 tests tell only whether the person has the virus, not what strain it is.

Ozer said there is also the possibility there is a third or fourth strain that has not been discovered.

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“Most definitely, yes,” he said. “This virus is constantly changing.”

The COVID-19 virus, like other viruses, constantly changes through mutation, and new variants of a virus are expected to occur over time, health officials say, but some change faster than others. Ozer said viruses like the flu and HIV evolves thousands of times faster than coronavirus.

“It does not look like this virus is any more severe,” Ozer said. “The other good news is of the tests that have been done so far, this variant does not seem to be resistant to the vaccine.

Some data suggests that with this new strain there is more virus in the mouth and nose, which might be part of the reason it spreads faster — there is just more of it.

Ozer said they have so far tested 180 samples at random. His team has been keeping an eye on virus changes since the pandemic began, but kicked it into hyperdrive once the strain was confirmed in the U.S.

Tracking new strains is expensive and time consuming. Doctors have to essentially sequence and unravel the genetic code of the virus in each sample.

Last year $3 million was given to labs and academic centers across Chicago in tandem with Rush University Medical Center and the city to step up surveillance and keep track of any further changes to the virus.

The Centers for Disease Control earlier this week announced that all international passengers headed to the United States will first need to show proof of a negative coronavirus test, effective on Jan. 26. The new policy requires all air passengers, regardless of vaccination status, to get a test for current infection within the three days before their flight to the United States departs, and to provide written documentation of their test results or proof of having recovered from COVID-19.

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