(MILWAUKEE) -- Milwaukee Public Schools reinstated the school district's mask mandate Tuesday after just one day of making face coverings optional for students.
In a press release, MPS cited "significant transmission" of COVID-19 within the city as the reason for the mandate returning. Starting Wednesday, all students through 12th grade and staff will be required to mask up while inside district buildings.
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MPS said the district can go back to a mask-optional policy if school leaders determine risk is low for viral transmission within the city and within the school district over the next few weeks.
"People are tired. I'm tired, I'm sure you're tired, we're all tired of the pandemic," Milwaukee County Chief Health Policy Advisor Dr. Ben Weston told ABC News. "We're tired of wearing masks, we're tired of distancing, we're tired about thinking anything related to COVID. But nonetheless the pandemic continues and the virus continues, and in the city of Milwaukee and in Milwaukee County, we're seeing increases that reflect the need to rethink mitigation measures."
In late March, the MPS board voted during its monthly meeting to make masks optional starting April 18, but warned face coverings would return if cases began rising. MPS did not respond to ABC News' request for comment. MPS has been "using objective measures" and "a data-informed approach to mitigation measures," Weston said.
As defined by the Centers for Disease Control and Prevention, Milwaukee County is still considered an area with "low" community levels of COVID-19. However, the city is reporting an increase in cases. According to the City of Milwaukee Health Department, there is "substantial" transmission of the virus with 58.1 confirmed cases per 100,000 people.
Weston said COVID cases have risen 200% over the last three weeks from 34 new cases per day to 104 new cases per day. Additionally, he shared the test positivity rate is back over the 5% threshold for moderate transmission. He said the reasons for the increases is "multifactorial" and includes variants.
"It's pretty likely the BA.2 variant is having a major impact on the increase that we're seeing. It's the most transmissible variant we've seen yet throughout the pandemic," he said.
Weston also attributed the rise in cases due to a low vaccination rate. Data from the Milwaukee County Office of Emergency Management shows 61.9% of residents in the county have received at least one COVID-19 vaccine dose, far below the national average of 77.4%.
As COVID infections rise, Weston urged Milwaukee residents to consider their risk tolerance and to use layers of protection including potentially wearing a mask in indoor public settings and getting vaccinated and boosted.
"I know it sounds like a broken record but vaccination is an important message now," he said. "During the height of omicron, COVID is front of mind for a lot of people so more went out and got vaccinated. Well, the vaccine only does so much for you if you're at the peak of a surge. It takes weeks for that immunity to kick in."
Weston added, "Now is the perfect time to get it because we don't know what comes next and because what BA.2 tells us is the pandemic isn't over and variants will continue to come."
The school district is not the only agency in the city to reverse its policy on masks.
Earlier Tuesday, Milwaukee County Transit System announced face coverings would be optional for riders on county buses. However, later in the day, it announced the mask mandate would remain in place "out of an abundance of caution" due to rising case counts.