After months of decline, COVID-19 cases have risen again nationwide and in Illinois where, according to state data, the number of new cases recently doubled in a period of nine days.
Illinois saw 460 new cases on July 12, and by Wednesday, the number of new daily cases was reported to be 958, according to the Illinois Department of Public Health.
Generated by the fast-spreading delta variant, climbing COVID metrics have even prompted some U.S. municipalities and governments to bring back mitigations like indoor mask mandates.
Such steps haven't been taken yet in Illinois and the Chicago area, but government officials say the additional precautionary measures are possible.
Calling on anyone who is unvaccinated to get vaccinated, Illinois Gov. J.B. Pritzker emphasized Tuesday that stricter mitigations could return for areas seeing a rise in COVID cases.
Chicago has also seen upticks in both average daily cases and test positivity.
Lightfoot said Tuesday that while numbers are still well below the spikes seen during the peak of the pandemic, "it's still a concerning development that we want to not only stay ahead of, but to quash completely."
The mayor's remarks come at a time where the average daily number of new cases in Chicago is up to 90 per day - a 69% increase over last week.
The city's average daily case rate was at 41 per day the week before that, meaning it's more than doubled in roughly two weeks - though it is still significantly lower than the more than 700 cases per day the city was seeing earlier this year and last, before vaccines were widely available.
Hospitalizations and deaths are down in Chicago - 11% and 13%, respectively, since last week - but the positivity rate in testing is up to 1.5% from 1% last week.
Along with increasing case numbers, Illinois has also seen an uptick in new hospital admissions for COVID-19-like-illnesses since the beginning of July.
A total of 37 admissions were reported on July 6. By Wednesday, the number of reported admissions had gone up to 60, according to IDPH.
Illinois officials say they plan to continue urging vaccinations in hopes of keeping the numbers from reaching even higher.
"For anybody listening who isn't vaccinated, please get vaccinated," Pritzker said earlier in the week. "It will save your life."