All students and staff in Jefferson County schools will be required to wear masks beginning Tuesday, the county’s public health agency announced late Monday, overriding a more limited policy instituted by the public school district there.

Jefferson County Public Schools announced in late July that students between the ages of 3 and 11, who are not currently eligible to get the COVID-19 vaccine, would be required to wear masks for at least the beginning of this school year. It also required unvaccinated employees be masked and encouraged unvaccinated older students to don face coverings, too. The district’s first day of school was Tuesday.

But Jefferson County Public Health issued an order Monday requiring everyone — regardless of vaccination status — to wear masks in schools, from pre-kindergarten through 12th grade. The order applies to all schools in the district, not just public schools. It also removes the option for students and staff to apply for a religious exemption; the order limits exemptions to medical requests.

The mandate extends to all child care settings and applies to children 2 and older. 

In its order, the public health department wrote that case rates for all age groups below the age of 20 have spiked in recent weeks compared to the same time last year. The rate for children 4 and younger increased nearly 78% from Aug. 8, 2020, to the same date this year. The rate for the 5-to-11 age group spiked 131%, and 12-to-19 jumped 62.1%. The latter group, though its percentage increase was greatest, has the highest current rate.

“Prevention strategies and particularly universal masking have proven effective at slowing the transmission of COVID-19 in school and childcare settings,” the agency wrote. “Multiple studies indicate that wearing a Face Covering reduces new infections, that Face Coverings are safe, and do not raise CO2 levels or reduce O2 levels to levels of clinical importance.

“Furthermore, Face Coverings may prevent disruptive quarantines in higher risk settings,” it continued. “Additionally, masking has been demonstrated to reduce school-associated COVID-19 transmission from secondary transmission rates of 11-27% in schools without masking to 1-4% in schools with universal masking policies.”

Whether to mask students in schools has become a highly debated topic, including in the metro area. Parents in Jefferson County protested the district’s already limited policy shortly after it was announced. After the Cherry Creek School District recommended masking but did not require it, scores of doctors protested that decision. On Monday night, a split group of parents implored the Tri-County Board of Health to either institute or withhold a mask requirement. Some called it an infringement on personal freedom while others said it was a needed tool to keep students in school and protect their health.

The Tri-County board will vote Tuesday afternoon on whether to require masks in the districts under its authority in Adams, Douglas and Arapahoe counties.

Denver Public Schools will require universal masking in indoor settings, the district announced this month.