While the District is set to ease its indoor masking requirement on Monday — impacting office buildings, retail stores, gyms and more — colleges and universities across the city say their own mask policies are staying in place.

Since returning to full-scale in-person learning in August, D.C.'s major universities have required students and employees to wear masks in most indoor settings, and all but Catholic University have required coronavirus vaccinations. Now, as the holidays approach, university officials and public health experts say mask-wearing will remain essential in protecting against virus surges.

“You probably don’t want to open this up for more transmission by telling people you can take off your masks in the classroom,” said Lynn R. Goldman, dean of the Milken Institute School of Public Health at George Washington University. “We’re not ready yet to say that it’s going to be safe for our community.”

On Friday, GWU announced that its mask mandate will stay in effect for all university-owned or university-operated facilities until further notice.

As of Saturday, D.C. met the CDC’s definition for “substantial” transmission of the coronavirus. Mayor Muriel E. Bowser (D) said Tuesday that children, adolescents and young adults in the District had experienced the highest number of cases during the pandemic’s third wave, which started in June, although few have needed hospitalization.

The impact of the District’s shift on masking rules was not immediately clear for university campuses and buildings. Bowser’s office said indoor masking in D.C. will continue on public transport and inside schools, libraries, child-care facilities, congregated facilities, and D.C. government facilities “where there is direct interaction between employees and the public.”

A spokesperson for Catholic University said that it had reached out to Bowser’s office for clarity on the requirements and was told that “schools” does include institutions of higher education. Catholic, which estimates it has had 35 total coronavirus cases since Aug. 9 and just three active cases, will continue its policy that faculty, staff and students wear a mask whenever they are in a shared space indoors.

“If there is an opportunity to lift the mandate, we will assess it and revise the policy when circumstances warrant,” Catholic University said in a statement Thursday.

Other schools said they were taking a similar “wait-and-see” approach.

Howard University’s mandate, which includes masking in groups outdoors, will continue for the duration of the fall semester, spokesman Frank Tramble said.

Thirty-eight coronavirus cases were reported at Howard during a tumultuous first week of the fall semester, and infection numbers remained elevated throughout September. But thanks in part to its implementation of masking and vaccination requirements — 98.7 percent of Howard’s students and 80 percent of its employees are fully vaccinated, according to Tramble — the campus now has reported single-digit student cases each week since early October.

“Along with our vaccine requirement and routine testing, the use of masks has directly contributed to low covid-19 cases throughout the semester and a marked decline in positivity over the past month,” Tramble said.

Georgetown University announced Tuesday that its mask requirement will remain in effect at least through the end of the semester. American University said in a statement that it will continue to require masks indoors except for those who are alone in private offices or residences, when eating or drinking, and a few other circumstances. Trinity Washington University, which mandates masks in public spaces indoors and encourages them in groups outdoors, will reevaluate its policies in January, a university spokesperson told The Washington Post.

Staying the course with masks — especially as the delta variant continues to spread — makes sense for universities, public health experts agreed.

“Requiring masks sends a really clear message that this is to protect everyone and to make sure that campus is a safe place to be and to learn and to maintain operations,” said Crystal Watson, an assistant professor of environmental health and engineering at Johns Hopkins University Bloomberg School of Public Health. “Frankly, if you have big outbreaks on campus, in-person classes at some point can be completely disrupted.”

In the summer and early fall, professors nationwide voiced concerns about the decision to return to classrooms amid the delta variant. But many expressed that mask usage would help ensure a safer work environment.

In addition to vaccination and mask rules, D.C. universities have also offered free-of-charge coronavirus testing, combined with contact tracing.

Each part of the covid-19 strategy, Goldman and Watson said, works together to keep campuses open.

“Schools that have been most successful, I think, have been doing some routine testing of even vaccinated people on campus, because we know if someone does get sick and they’re vaccinated … they are not less likely to pass it on to someone else,” Watson said. “… So while they’re less likely to get infected in the first place, it’s important to mitigate these outbreaks on campus as best we can.”