Cohorting and Contact Tracing

Cohorting has not been a large focus at the high school throughout hybrid learning, though it is recognized as an effective strategy to prevent outbreaks of COVID-19. When dividing students into multiple smaller cohorts, schools are often able to decrease the number of potential close contacts of any given student, therefore preventing large outbreaks.

Many districts have split grades into many small cohorts to minimize close contact amongst students, though the high school did not utilize this strategy. However, it did divide into two large and distinct cohorts: Monday-Tuesday (MT) and Thursday-Friday (RF).

Assistant Head of School Hal Mason said that grades 10-12 were assigned classrooms in different sections of the high school based on grade level in order to minimize the spread across grades. For example, senior classrooms are typically on the fourth floor, and sophomores are typically on the first floor on the Welland road side of the 115 campus.

According to Medical Director of Payment & Care Delivery Innovation at MassHealth, Instructor in Medicine at Harvard Medical School Lakshman Swamy, the major flaw in cohorting tactics at the high school has been the shift in focus and intention.

“Cohorting was being used to prevent huge outbreaks, and now cohorting is more to make contact tracing easier, which is very different,” Swamy said.

Mason also said that it is nearly impossible to find a group of students at the high school who share an identical or semi-identical schedule, meaning creating smaller cohorts is not feasible. He also recognized that that is not what high school should be like, and that the high school experience must include interacting with and learning with a variety of different students.

Because of the enhanced safety measures that have been implemented, the town has decided the high school is ready to move away from cohorting, regardless of how this may create more work for the school’s contact tracers, though Brookline has excelled in contact tracing thus far.

“I think it’s perfectly reasonable for a teacher to see lots and lots of students, as long as those protections are in place for that teacher, and as long as they’re still able to largely maintain distance and wear face masks,” Swamy said.

Gacioch agreed that the high school is ready to move away from cohorting.

“In terms of actual prevention of people becoming infected, {cohorting is} probably not as important at this point, and we should be focusing more on doing a really good job with masks and other PPE, keeping up our game on ventilation and those will do that work,” Gacioch said.

Currently, classmates or people that were interacting masked and distanced are not considered close contacts of someone who contracts COVID-19. Mason affirmed that there is no plan to change this protocol due to the low rate of in-school transmission.

Contact tracing has been carefully and successfully executed by school nurses and will continue this way. Nurses have been conducting rigorous and very specific interviews with students who test positive in order to identify all close contacts. Due to the low case count, Mason said this type of contact tracing is working very well.