As COVID-19 case counts increase, some Philadelphia schools have opted to shift to virtual learning until the winter break and immediately after the holidays.

Mastery Charter Schools in Camden and Philadelphia will move to remote learning effective Thursday “in light of the stark rise in COVID-19 cases across the Greater Philadelphia region,” officials told Mastery families. Students will remain virtual through Jan. 14, returning to in-person classes on Jan. 18.

Olney Charter High School had previously announced a pivot to virtual instruction through the first week in January. After Olney student Alayna Thach died of COVID-19 last week, staff have raised concerns over COVID-19 protocols and many called in sick Monday, initially forcing the shift to remote learning.

But though 19 of more than 200 Philadelphia School District schools are temporarily closed because of virus cases, officials said they are not changing course for January in-person learning plans — for now.

“At this point, we are not planning to do anything than be in person in our schools on Jan. 4,” spokesperson Monica Lewis said. But, she said, that could change.

“This is a very evolving situation, and we’re all working very closely with Philadelphia Department of Public Health,” said Lewis.

Health Commissioner Cheryl Bettigole said, in a letter to school communities, that she “supports the decision by the School District of Philadelphia to keep schools open for in-person learning and strongly encourages all K-12 schools in Philadelphia to do so whenever possible. While individual classrooms, grades, or schools may need to temporarily pause in-person learning if cases in those groups are high, we do not advocate closing schools broadly at this time despite the current COVID surge.”

Over 30 staff at Fels High School called out Thursday, forcing that school, in the lower Northeast, to go virtual for the day. Staff are worried about multiple positive cases at the school, inconsistent mask compliance, and a large number of unvaccinated students, one said.

A number of Philadelphia schools have already gone virtual because of case counts, according to the city’s Health Department: Ethan Allen, Blankenburg, J.H. Brown, Carnell, Clemente, Fox Chase, A.B. Day, McDaniel, A.S. Jenks, Kenderton, Mifflin, McKinley, Muñoz-Marín, Pennypacker, Penn Treaty, Richmond, Sullivan, Waring, and Welsh are all temporarily closed.

Separately, Dobbins High abruptly dismissed early Tuesday because of multiple positive cases; one teacher said there were not enough staff to cover classes.

Families and staff were told the school would “temporarily close for a minimum of 48 hours ... to help stem the spread of the virus,” according to a letter sent to the Dobbins community.

Superintendent William R. Hite Jr., in an email to staff, directed staff and students to take laptops home over the break and said the district would begin to crack down on its mask protocols, sending home those who refuse to comply.

Robin Cooper, president of the district’s principals’ union, said schools are “drowning,” managing surging case counts, staff absences, and COVID-19 protocols with little guidance and support that she said leads to an undercount of virus cases.

“It’s dangerous,” said Cooper. “They have protocols and they’re not paying attention to them.”

Cooper said she believes the district should return virtually after break.

“There’s no way we’re ready to come back in January,” she said.

Philadelphia Federation of Teachers president Jerry Jordan said he shared members’ concerns regarding rising case counts in schools but stopped short of recommending a shift to virtual learning. He sent a letter to Hite Wednesday, sharing concerns about masking, contact tracing, and other protocols he said are loosely enforced.

“In-person learning is hands down the most effective method of delivering and receiving instruction,” said Jordan. “But our position is that schools have to be safe. If we have to go virtually until such time as the mitigation strategies can be put in place, that’s what will have to happen.”

District teachers must either be vaccinated or submit to twice-weekly COVID-19 testing; the school system said months ago it would institute testing for asymptomatic students, but that has not yet begun.

And some city schools still lack key personnel — including nurses — complicating the situation.

“It really makes me shudder to think of a school in this environment without a full-time nurse,” Jordan said.