93 cases of new variant of omicron reported in Illinois
State officials reported 93 cases of a highly contagious subvariant of omicron were detected in Illinois from Jan. 31 to March 5.
The latest mutation of COVID-19, BA.2, is more infectious than the first version of omicron, which caused a surge of cases across the U.S. in December and January, studies show. However, BA.2 resembles its predecessor in typically causing milder infections compared to earlier COVID-19 strains, health experts said.
The BA.2 cases represented approximately 1.4% of COVID-19 variants detected over five weeks, the Illinois Department of Public Health said.
The new strain is the predominant variant in places such as South Africa and Denmark. The U.S. Centers for Disease Control reports it currently constitutes 11.6% of new cases nationwide, said Dr. Sharon Welbel, infectious disease specialist for Cook County Health.
A study from Denmark "looked at 8,500 households and the conclusion was BA.2 was 33% more infectious than the original omicron and other studies have come up with similar numbers," Welbel said.
"But there's really no evidence yet to say it causes more severe disease, and that's the good thing. It also looks like our vaccines seem to have a similar level of protection to this variant of concern" as they do to the original.
As with typical omicron infections, "we see more virus in the upper respiratory tract than the lower respiratory tract so therefore much less pneumonia," added Welbel, CCH director of hospital epidemiology and infection control.
Because just a small number of variants are sequenced there are more cases circulating in the community than officially recorded. BA.2 is also referred to as "stealth" omicron because it's harder to detect than the original and requires an extra genomic sequencing step.
New cases of COVID-19 totaled 1,398 Thursday, with 42 more deaths from the respiratory disease, the Illinois Department of Public Health reported. The seven-day average of COVID-19 infections increased to 1,146 cases for the first time since March 1.
Illinois hospitals were treating 715 COVID-19 patients Wednesday night, less than the seven-day average of 749.
The state's positivity rate for COVID-19 cases is 1.2% based on a seven-day average.
Total cases statewide stand at 3,043,893, and 33,052 Illinoisans have died since the pandemic began.
On Wednesday, 10,014 more COVID-19 shots were administered. The seven-day average is 9,897.
So far, 8,592,000 people -- 67.8% of Illinois' 12.7 million population -- have been fully vaccinated, according to the U.S. Centers for Disease Control. The CDC defines fully vaccinated as two doses of the Pfizer or Moderna vaccine, or one dose of Johnson & Johnson's.
Of those people who are fully vaccinated, 49.4% have received a booster shot.
The federal government has delivered 23,940,645 doses of vaccine to Illinois since distribution began in mid-December 2020, and 21,208,108 shots have been administered.
Labs processed 131,502 virus tests in the last 24 hours.