There has been mixed reaction from students and parents across the city. Many said they will likely keep wearing their face masks for now - especially at schools with lower vaccination rates - despite the mask mandate ending. And that's something the CPS CEO recommends, as well.
"Unfortunately, we do have schools that have very low vaccination rates and we do ask families to please one first get a vaccination, please," CPS CEO Pedro Martinez said. "But if they're not vaccinated, we strongly encourage them to wear their masks."
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Some families at Penn Elementary on the West Side were heeding that warning.
"We all are fully vaccinated but I would rather my children continue to wear their mask because, just because today it stops, doesn't mean that COVID isn't still going around," parent Smaika Austin said.
"I am still going to let him wear it," said another parent identified only by her first name, Theresa. "It's up to other kids and other parents on how they choose to vaccinate their kids or not vaccinate. It's a big controversy about it, but I'm just going to stick to what's been working for us."
The current test positivity rate in the city is 0.7%, but the Chicago Teachers Union is pushing back. The CTU has filed a labor grievance, saying the decision violates their safety agreement set back in January.
"That was expected, but it's active litigation so I won't say much," Mayor Lori Lightfoot said. "We should be grateful we're at the place we are today at 1% positivity."
The union said the mask optional policy breaks the agreement to keep masks on through the end of the school year.
"You know, the CTU are our valued partners and we'll continue to work with them," Martinez said. "But when we have to follow the science, and the second, we have to make sure we keep our flexibility."
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Over a third (37%) of schools have fewer than 25% of their students fully vaccinated, and only 10% of schools have 70% of their students fully vaccinated, according to a previous report.
Overall, 49% of age eligible CPS students are fully vaccinated. But that number is driven up by schools, many on the North Side, with high rates. The lowest is Penn Elementary on the West Side at 5%.
Students who still chose to wear their masks Monday had different reasons, but many said they just want to stay on the safe side.
"I have a lot of immunocompromised friends, so it's not just for me; I wanna keep them safe, you know, it's really not fair that they're immunocompromised," Northside College Prep student Gayathri Garapaty said.
"I just think about my family and how COVID has affected them, and I think it's really important to wear your mask and protect myself, my family and others as well," classmate Erica Leon said.
But some students at Northside are making the choice to go without their masks, hoping others will respect their decision.
"In the hallways, I'm not gonna wear it just because we have the highest vaccination rate of any other school, so it doesn't make sense, and I probably won't wear it in gym class either," Soren Sandberg said.
At Northside, some students feel better knowing most of their classmates are still wearing them.
"I don't really want to stand out too much so I feel like relieved," Amargoe Gagan said.
CPS said if health metrics start to move in the wrong direction, the district could re-instate the mask policy.