The senator says she's experiencing "mild symptoms."
As the COVID-19 pandemic has swept the globe, more than 5.3 million people have died from the disease worldwide, including over 806,000 Americans, according to real-time data compiled by Johns Hopkins University's Center for Systems Science and Engineering.
About 61.4% of the population in the United States is fully vaccinated against COVID-19, according to data from the Centers for Disease Control and Prevention.
In Illinois, 11,858 new cases were reported on Thursday -- the highest daily case number of all of 2021, ABC Chicago station WLS reported, citing state health officials.
Illinois confirmed its second omicron case Wednesday, detected in a suburban Chicago resident. That person is asymptomatic and vaccinated, WLS reported.
The Centers for Disease Control and Prevention has signed off on its advisory committee's recommendation that people who have a choice should get an mRNA vaccine, either Pfizer or Moderna, over the single-shot Johnson & Johnson vaccine.
The updated recommendation comes after a review of new CDC data on rare blood clots linked to the J&J vaccine.
"Today's updated recommendation emphasizes CDC's commitment to provide real-time scientific information to the American public," CDC Director Dr. Rochelle Walensky said in a statement. "I continue to encourage all Americans to get vaccinated and boosted."
The new omicron variant makes up nearly 100% of the strains found in wastewater samples in Orlando, Florida, officials said Thursday.
"It escalated rapidly," Orange County Utilities spokeswoman Sarah Lux told ABC News.
In its first test for the variant last Thursday, the department found no evidence of omicron in the community's wastewater, she said. On Saturday, it represented about 30% of the strains found in the samples, and by Tuesday, nearly 100%.
"So, we're talking about zero to nearly 100 in a matter of a week," Lux said.
All parts of the county are seeing an increasing presence of the omicron variant, she said. The southern area, home to the theme parks, has seen the highest amount of virus remnants, followed by the eastern area, which is home to the University of Central Florida.
-ABC News' Arielle Mitropoulos
The CDC's advisory committee recommended Thursday that people who have a choice should get an mRNA vaccine, either Pfizer or Moderna, over the single-shot Johnson & Johnson vaccine after a review of new CDC data on rare blood clots linked to J&J.
The vote was unanimous.
The rare blood clots are not a new safety concern and the vaccine has already become far less common in the U.S. after it was given an FDA warning label about the clotting condition. But more data that confirmed a slightly higher rate of clotting cases and deaths than was previously reported caused the CDC and FDA to take another look at the data this week.
The CDC has confirmed nine deaths and 54 cases from the severe clotting event, thrombosis with thrombocytopenia.
There could also be more cases and deaths because TSS is under-diagnosed and could be underreported, the CDC said.
The clotting is more common among women in their 30s and 40s but has been seen in adult men and women of all ages.
The experts said J&J should not be taken off the shelves and is still far more beneficial than not getting any vaccine at all.
-ABC News' Cheyenne Haslett
