Illinois cases of a COVID-19 variant first discovered in the United Kingdom that is believed to be more transmissible rose 45% in the past seven days, according to data released Thursday by the Illinois Department of Public Health.
In all, 1,286 cases involving the variant, known as B.1.1.7, have been found in samples of COVID-19 positive tests from Illinois since Jan. 15, officials said.
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.
The variants helped fuel a spring surge of COVID-19 cases in Illinois, with the Peoria region as well as Chicago and suburban Cook County hit particularly hard, according to data from the Illinois Department of Public Health.
That surge appears to be easing, and cases involving the variant are not rising as fast as in previous weeks, according to the data.
A total of four COVID-19 variants believed to be more transmissible have been discovered in Illinois.
Cases of the P.1 variant, which was first discovered in Brazil, jumped 69% in the past seven days to a total of 367 cases, officials said. The variant was first discovered in Illinois on March 5, according to state data.
Cases of a variant known as B.1.427/B.1.429, which was first identified in July 2020 in Los Angeles County, increased 27% in the past seven days to a total of 106 cases, according to state data. The variant was first identified in Illinois on March 25.
Twenty-one cases of the variant first discovered in South Africa, known as B.1.351, have been identified in Illinois since Feb. 11, according to state data.
More study is needed about the infectiousness and severity of the California and Brazilian variants, according to Illinois Department of Public Health officials.
To prevent the spread of COVID-19 and its variants, Illinois officials are urging people to wear a mask, stay 6 feet away from those who are not in their household, avoid gatherings and unnecessary travel, and wash their hands often.
Data suggests current vaccines will be effective and safe in providing protection against the South African and U.K. variants, officials said.