More than twice as many students tied to outbreaks at Colorado K-12 schools have COVID-19 as did at the worst point of the pandemic in early December, but it’s unlikely families will see the mass exodus to online learning they did last year.

The Colorado Department of Public Health and Environment reported 156 outbreaks in schools as of Wednesday afternoon, with 250 staff members and 1,900 students listed as infected. Schools aren’t required to report an outbreak if they have five or fewer cases, or if those cases don’t have a clear link, such as a shared class, extracurricular activity, or bus route.

At the peak in early December, 211 schools had outbreaks, affecting 387 staff members and 863 students. At the time, vaccines weren’t yet available for teachers or older students, but fewer school districts had in-person classes than now, and mask-wearing was required by the state.

Children and teens accounted for about 26% of COVID-19 cases in Colorado in the second week of September (the last week with complete data), but few become seriously ill. The state reported 14 people younger than 18 were hospitalized for COVID-19 as of Tuesday.

Schools that transitioned to online learning last fall largely did so because they had too many staff quarantining to manage classes, rather than because too many students had gotten infected.

Now, the state doesn’t require staff who are fully vaccinated to quarantine after exposure, if they aren’t showing symptoms. A handful of schools did temporarily return to remote learning since classes resumed in August, however.

The majority of school outbreaks involved 10 or fewer people, but 18 schools had outbreaks that infected 30 or more students and staff members.

The largest outbreaks were:

• Loveland High School, Thompson R2-J School District: 46 student cases, three staff cases
• Grand Mesa Middle School, Mesa County Valley School District 51: 48 students
• University Schools, Greeley-Evans School District 6: 39 students, six staff
• Douglas County High School, Douglas County School District: 35 students, seven staff
• Power Technical Early College, Falcon District 49: 35 students, seven staff
• Mesa Middle School, DCSD: 35 students, four staff
• Northridge High School, Greeley-Evans: 37 students, two staff
• Eagle Valley High School, Eagle County Schools: 37 students
• Mountain View High School, Thompson: 34 students, one staff
• Resurrection Christian Middle/High School: 24 students, 10 staff
• Vista Ridge High School, District 49: 31 students, three staff