Students and parents streamed toward Saint Brendan School in Dorchester on a recent morning, part of a middle-class scene that's largely disappeared from the Boston landscape. Kids squealed as they jumped over snowbanks while mothers and fathers pushed strollers or walked dogs. A longtime neighborhood crossing guard greeted everyone by name.

It's a throwback to the 1950s — and to pre-pandemic times.

Most public school students in Boston, the state’s largest school district, have not returned to in-person learning for nearly a year due to the pandemic. But greater Boston’s Catholic schools, the state’s second largest school system, stretching from Plymouth to New Hampshire, reopened in the fall. It’s a stark contrast, one that’s made Catholic schools attractive to families fed up with remote learning and willing to pay for in-person instruction.

After decades of fading enrollment, Catholic schools have seized on the renewed interest like a lifeline. Nuns and religious educators are talking about pandemic marketing strategies.

“How well are we marketing our product to those families?” asked Sister Dale McDonald in a recent webinar held by the National Catholic Educational Association. “How are we hearing from them, whether or not this is what they really would want to choose for their students?”

Catholic superintendents in Boston, Worcester, Mass., and Providence, R.I., said that safety sells in a pandemic. But they also said operating schools in these times comes with limitations. Both the Boston and Providence superintendents reported that dozens of teachers decided not to return when schools reopened, and some students took the option to learn remotely. But the superintendents also said that to their knowledge, no one has been hospitalized as a result of an outbreak in a school. In urging public schools to reopen, Gov. Charlie Baker has at times cited the safety record of Catholic schools to help make his case.

Thomas W. Carroll, superindentent of schools for the Roman Catholic Archdiocese of Boston, said that he was nervous when he reopened schools in September, despite taking every precaution. They opened five days a week, so he was all in.

“What we said when we opened is we would follow the science,” he said. “As long as it was safe, we would keep our schools open.”

By winter, 4,000 new students had enrolled. Carroll said that's one of the biggest enrollment spurts in the nation, even though overall numbers are still down slightly, to about 35,000 students. (Boston Public Schools have 54,000 students.) Seventy-five of the archdiocese's schools are currently open full time, while the other 25 meet in person part-time under a hybrid model.

Carroll acknowledged that "following the science" hasn't been a hallmark of the Catholic Church's teachings. “The irony of that is not lost on me,” he said.

But the federal Centers for Disease Control and Prevention and state guidance have been instrumental. The schools also have waitlists partly because of the archdiocese's adherence to strict three- to six-foot spacing in classrooms. Student activities are also strictly curtailed, masks are required at all times and even bathroom breaks are monitored for cleaning and contact tracing purposes.

The exacting discipline Catholic schools are known for has also been helpful in a pandemic. Everyone from students to teachers to cleaning crews has a strict schedule. New rules galore regulate parent drop offs and socializing.

Jordan Maurice, a junior at Bishop Fenwick High School, in Peabody, said that pandemic schooling is different. For one thing, he can’t stop and chat with his history teacher or football coach because it disrupts the flow through school hallways.

“So it's definitely weird, that you can't just have even the littlest interactions that made it normal,” Maurice said. “They just got taken away from me.”

But Dan Ferris, superintendent of Providence's Catholic schools, said that kind of rigor has kept the 35 schools in the Rhode Island Diocese mostly COVID-free outside of a handful of cases, primarily at the high schools.

Small classes have helped, too. The student to teacher ratio is about 13 to 1. One of the biggest expenses has been hiring additional substitute teachers when regular teachers need to quarantine, along with more school nurses and cleaning crews. Federal funds have helped pay for costly plexiglass barriers, table dividers and new outdoor tents.

“I'm not about to run a victory lap,” Ferris said recently.

Despite the precautions, about 40 teachers did not return to Providence's Catholic schools last fall. Enrollment also fell by more than 6%.

Ferris said he’s also concerned about learning loss, particularly among students learning English and kids with special needs who would benefit from seeing their teachers' face unmasked.

“These are the students that I am most concerned about,” he said. “Teaching under a pandemic, it's not the same. And for students with different learning needs, it's very hard to provide that kind of specialized instruction.”

Some lucky families have received financial support.

Maurice, the senior at Bishop Fenwick, got financial support from the Catholic Schools Foundation, which funded more than $6 million in aid to schools in the Boston Archdiocese.

Yet that philanthropy and an emergency fund have not been enough to curb enrollment losses and school closures, which have disproportionately affected urban areas serving communities of color, according to the National Catholic Educational Foundation.

Some newcomers during the pandemic have been able to enroll their children without aid.

Caitlin Thurston, a nurse, said she and her husband, a foreman at a hospital, got their son into one of the last open kindergarten spots at the Immaculate Conception elementary school in Lowell.

Thurston said she was anxious sending him off and definitely didn't need another bill to pay. But choices were few.

“My husband and I were in it,” she said, referring their heavy work schedules. “So we never had the opportunity to just stay at home and have everything delivered and be afraid all the time. We just had to go to work.”

Her son is thriving, she said, and she may keep him enrolled there if the school accommodates his special needs.

Scraping money together for tuition is harder for some families. Andrea Papadopoulos-Walsh was in-between jobs when the pandemic closed classrooms at her daughter's public school in Peabody. Remote learning didn't go well.

“It was awful to watch a kid who did so well and loved it so much just completely struggle and fall apart,” she said.

Walsh’s mother agreed to help pay the $4,000-a-year tuition at Saint John the Baptist School in Peabody. No one has regretted it. Walsh said her daughter left a brand new public school in Peabody that was closed to attend a 100-year-old red brick school with fans in the windows. She hasn't heard any complaints.

“She loves her uniform,” she said. “I think she'll wear it next year even if she goes back to public school.”