CDC study shows teachers could play ‘central role’ in Covid spread at schools where masks aren’t worn

A student is seen on the steps of the closed public school PS 139 in the Ditmas Park neighborhood in Brooklyn of New York, the United States, Oct. 8, 2020.

Michael Nagle | Xinhua News Agency | Getty Images

School teachers and staff may play a “central role” in transmitting Covid-19 within schools where social distancing and face covering precautions aren’t followed, and vaccinating them against the disease could help return students to the classroom safely, according to a new federal study published Monday.

The U.S. Centers for Disease Control and Prevention investigated the coronavirus’ spread within eight Georgia public elementary schools in the same school district between Dec. 1 and Jan. 22, which included 24 in-person learning days. During this period, the average number of cases per 100,000 residents in the county increase nearly 300%, the study said.

The federal health agency, along with state and local public health departments, found nine Covid-19 “clusters” involving 13 educators and 32 students at six of the eight elementary schools.

The median cluster size — defined as three or more linked Covid-19 cases — was six people, and an educator was the “index patient,” or the first identified case, in four of those clusters, the CDC found. A student was the first patient in one cluster, while the other four clusters had an unidentifiable index patient.

All but one of the clusters involved “at least one educator and probable educator-to-student transmission,” the study found.

“These findings suggest that educators can play an important role in in-school transmission and that in-school transmission can occur when physical distancing and mask compliance are not optimal,” the CDC researchers wrote in the study.

In the study, the CDC researchers said they conducted interviews with parents, educators and school principals and studied seating charts, classroom layouts, physical distancing and compliance with recommended mask use during in-person learning to determine case links.

They found that all nine of the clusters involved “less than ideal” adherence to social distancing recommendations. Students sat less than 3 feet apart and, in many cases, the virus’ spread among and students could have spread during small-group sessions, according to the study.

The findings come just over a week since the CDC unveiled new guidance on how schools can safely reopen for in-person learning despite the spread of the virus. Among the many recommendations, the CDC advises districts to phase in their reopening plans in accordance with the severity of the outbreak in their areas.

It also says schools should adopt “essential elements” in resuming in-person learning, including wearing masks, physical distancing and monitoring the level of spread in the surrounding community. 

While the CDC advised states to prioritize vaccinating teachers and staff “as soon as supply allows,” the guidance did not recommend it for reopening. The study published on Monday, however, suggested that vaccinating educators could be important for protecting the most at-risk while reducing interruptions to in-person learning and potentially preventing the virus’ spread in schools.

“Although not required for reopening schools, COVID-19 vaccination should be considered as an additional mitigation measure to be added when available,” researchers wrote.

— CNBC’s Will Feuer contributed to this report.