As winter break ended, Ximena Santana received a confusing text message. It was from her Oakland, Calif., high school, reminding her to upload the results of the take-home coronavirus test she had been given. The problem was, she had never received a test.

She went back to school, a little wary. There, “no one asked us, ‘Hey, did you take your at-home test?’" By the second day, she and her friends noticed that large numbers of students were absent. Some were sick with covid-19, as case numbers surged nationwide because of the highly contagious omicron variant. Ximena’s friends were scared. She got scared, too.

“We were talking about how can we make school more safe,” Ximena said. Within days, they prepared a petition vowing to stay home until the Oakland Unified School District agreed to take steps, including offering KN95 or N95 masks, holding twice-weekly testing, and creating outdoor space for lunch when it rains.

They recruited some students with large social media followings to share the petition online, and by Thursday, the first day of the student sickout, the petition had more than 1,200 names.

“We’re annoyed. We’re kind of frustrated. Why haven’t they delivered on their promises?” said Ximena, a sophomore at MetWest High School.

Ximena and her Oakland friends have a lot of company. In cities across the country, student-led movements are emerging and gaining steam, with teens demanding better safety protections inside schools and, in some cases, pushing for a return to remote classes.

Nearly two years since the coronavirus hit, the adults — parents, teachers, administrators, politicians — have spent a lot of time and energy fighting over what schooling in a pandemic should look like. Now, for the first time in large numbers, students are rising up and demanding that they get a say, too — in places like New York City, suburban New Jersey, outside Washington and California.

Studies last year found scant virus transmission inside schools, particularly when masks were worn consistently, and that was before vaccines were approved for children and teens. Schools that have moved online this month have mostly cited staff shortages due to illness. But some students are not convinced it’s safe.

Thai Jones, a lecturer at Columbia University who studies radical social movements, said the rise of student activism amid the omicron threat reminds him of the youth movement for gun safety that sprang up after the 2018 mass shooting at a Parkland, Fla., high school and of ongoing teen-led advocacy around climate change.

“What ties those movements together is these are all times when grown-ups have failed young people, where the politics of adults have really let down teenagers,” Jones said. “And so young people have decided to take matters into their own hands.”

The protesters are savvy, Jones said, by protesting both virtually and physically. Petitions hosted online can go viral, earning national media coverage, while boycotting class forces administrators locally to pay attention, he said. Some student organizers are making clear that they do not want students gathering in groups for rallies or anything else while not in school, which would defeat their stated purpose of staying safe.

Most school systems are determined to keep classes in person, having witnessed the academic, social and emotional damage inflicted by virtual school. Last year saw significant pushback from teachers hesitant or outright opposed to teaching inside school buildings. There’s still some of that, notably in Chicago, where classes were canceled for a week while the teachers union refused to teach in person and the city refused to go remote. But this time, most unions have gone along with brick-and-mortar classes.

This week, 4,947 public schools had in-person learning disrupted in one way or another, according to tracking from Burbio, a data firm. That’s down from the previous week and remains a small share of some 100,000 K-12 schools nationwide.

But many students are not convinced this is a good thing, worried they will catch the virus or bring it home to elderly relatives. Students, Jones said, feel like they’ve been “so completely left out of the pandemic conversation.”

In New York City, students from more than 20 schools walked out of class Tuesday to demand an online schooling option and greater protections against the coronavirus. A viral video showed students streaming out of Brooklyn Technical High School, a large and prestigious public school. A student’s Reddit post about absent teachers, covid-19 risks and a lack of learning at another New York high school had more than 8,000 upvotes, which are similar to likes.

Cruz Warshaw, 16, a junior at Stuyvesant High School who helped organize the protest, said that New York City Schools Chancellor David Banks reached out after the walkout and said he wanted to meet with the students involved. A meeting is in the works, she said.

On Thursday, Banks said the city is discussing creating a remote option. “I do think we can come up with something because there’s enough political pressure that has been put on,” he said at a virtual meeting of the Chancellor’s Parent Advisory Council.

Warshaw said the students are going to wait and see what changes the city makes before deciding whether to organize another protest. She added that when they first announced the walkout, some commenters on their social media posts suggested that a bunch of kids weren’t going to accomplish anything.

“I think we’ve gotten pretty far as just a bunch of kids,” she said. “It definitely does feel empowering.”

In New Jersey, a high school senior started a campaign for virtual schooling in late December and won a minor victory when administrators with Princeton Public Schools opted to reopen every other campus except its high school in early January. School officials, who did not respond to a request for comment, said in a message to families that the campus would stay closed for a full week due to “staffing issues.”

Senior Harmonie Ramsden claimed otherwise: “We did it, everyone!” she wrote in an update to her online petition. “I’m so happy that the administration has decided to side with students in protecting our safety.”

In suburban Maryland, just outside the nation’s capital, students in two neighboring districts — Montgomery County Public Schools, the state’s largest, and Howard County Public Schools — have started online petitions calling for a reversion to online schooling until the omicron surge is spent. There are also plans for a walkout next Friday in Montgomery.

Hailey Enright, 16, a student at Gaithersburg High School who is helping organize the Montgomery walkout, said she felt inspired after watching a video of the New York demonstrations. “I thought maybe that would show MCPS something,” she said. “Also I’ve learned a lot in history classes about protests and everything.”

Elsewhere in the county, Zoe Cantor, a senior at Walt Whitman High School in Bethesda, was also feeling anxious as text messages started pouring into her phone shortly after the New Year.

“It was like: ‘This person has covid. That person has covid. Another person has covid. Did you know?’” she said.

Around the same time, Cantor opened an email from the school district of 160,000 saying that more coronavirus cases had been reported between Dec. 1 and Dec. 19 — roughly 1,500 — than were reported between the start of school in late August and the last day of November.

She pictured her high school, which is home to 2,000 students and where masks are required but the enforcement varies. She thought about lunchtime, when hundreds of kids pack into the cafeteria and remove their masks to eat. “And that’s when I got worried,” said Cantor, who is both vaccinated and boosted.

So last Friday, she wrote and published a petition on asking for “virtual learning right now.”

“Amid the recent surge of COVID cases in the country, specifically the omicron variant, it is unsafe to hold students in schools that do not mandate any social distancing and allow masks to be taken off,” the petition reads.

Not expecting much, Cantor texted the link to six friends and posted about it on her private Instagram, where she has 800 followers. But it took off and as of Thursday had more than 17,000 signatures.

The school district has said it is sticking with in-person learning, although officials recently promised to hand out test kits and deliver KN95 masks to students, as it has already done for staff. A school spokesperson did not return a request for comment.

Across the country, in Oakland, a boycott of classes informally began Thursday and students say it will continue until better masks and coronavirus tests arrive at their schools.

Ayleen Serrano, a 15-year-old sophomore at MetWest High, said she does not buy the arguments she is hearing from her school system — and adults generally — on the importance of in-person learning.

“The district is like, ‘Oh no, we shouldn’t do [remote school] because of the students’ mental health,’” Ayleen said. “Back when we were in online school, they didn’t care about our mental health. Now all of a sudden they start caring about it?”

On Thursday, some Oakland teachers stayed home in solidarity with students.

This week, the district appeared to respond to the health and safety concerns by announcing that it had distributed KN95 and N95 masks to teachers, and ordered 200,000 KN95 masks for students in the district, which enrolls about 50,000 children.

The district also said it had provided two HEPA filter air purifiers in each classroom and had ordered more covered dining sets for outdoor lunch. It said it would provide rapid tests to students in classrooms where there has been coronavirus exposure.

Ximena said the announcement was encouraging but she is waiting to see if the items materialize. “We will be continuing the boycott until the items they said they would give us actually show up to our schools,” she said.

Ray Hart, executive director of the Council of the Great City Schools, which represents urban districts, said any decision — stay open, or go remote, or something in between — will be met with complaints.

“Unfortunately, it’s a no-win situation,” he said. But he said that student activism is, on balance, a positive: “Anytime students can advocate for themselves and express their feelings about a circumstance or a situation is a good thing.”