(WTTW News)

Twenty-seven more cases of a COVID-19 variant first discovered in the United Kingdom that is believed to be more transmissible have been discovered in Illinois in the past five days, according to data released Tuesday by the Illinois Department of Public Health.

In all, there have been 69 cases involving the variant, known as B.1.1.7, in samples of COVID-19 positive tests since Jan. 15, officials said.

That is an increase of 64% since Feb. 25, according to the data. However, zero cases of the variant were discovered between Feb. 18 and Feb. 25, according to the data.

The variant has been found most often in Cook County, followed by Champaign, Lake and Kane counties, according to data provided to WTTW News by the Illinois Department of Public Health.

A single case of the coronavirus variant first discovered in South Africa, which is also thought to be more transmissible, was first reported by state officials on Feb. 11 and is so far the only confirmed case in Illinois, according to data from the Illinois Department of Public Health.

The COVID-19 virus — also known as SARS-CoV-2 — constantly changes through mutation, and new variants of a virus are expected to occur over time, officials said.

State and local health officials have said it is not surprising that the variants have been discovered in Chicago and Illinois but have urged residents to continue to wear masks, practice social distancing and get vaccinated when possible.

Data suggests current vaccines will be effective and safe in providing protection against the variant, officials said.

Contact Heather Cherone: @HeatherCherone | (773) 569-1863 | [email protected]