Feb. 22 (UPI) -- Teachers and staff "play a central role in in-school transmission" of COVID-19, highlighting the importance of vaccination for educators, according to a report released Monday by the U.S. Centers for Disease Control and Prevention.
Nearly half of all in-school cases in a Georgia district recorded between Dec. 1 and Jan. 22 were linked with "educator-to-educator" or "educator-to-student" transmission, the data showed.
Subsequently, 26% of household contacts of these school-associated cases later tested positive for the virus.
"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," CDC researchers said in the report.
Although the CDC stopped short of requiring teacher and staff vaccination for reopening schools for in-person learning, the agency said inoculating educators against the virus "should be considered as an additional mitigation measure to be added when available."
That essentially echoes guidelines the agency released earlier this month, which advised that teachers should have priority access to vaccines against COVID-19, but that their inoculation would not be a prerequisite for schools to reopen nationally.
Many districts across the country have instituted a "hybrid" mix of in-person and online learning to minimize crowding in schools.
President Joe Biden has said he wants most students in kindergarten through eighth grade returning to in-person learning five days a week by late April.
Roughly $130 billion of the $1.9 trillion COVID-19 relief bill currently being debated in Congress is aimed at helping schools reopen, including to reduce class sizes and modify spaces for social distancing, as well as to improve ventilation and airflow in school facilities, according to the White House.
"This study adds to a body of evidence that shows COVID-19 is transmittable in schools without the safety guardrails in place," Randi Weingarten, president of the American Federation of Teachers, told UPI, referring to the new report issued by the CDC.
She has previously said that while all teachers may not need to be vaccinated in order to safely reopen schools, many members of the union are concerned about bringing the coronavirus home and infecting their families.
"School buildings can be safe for teachers and kids, but the layered mitigation and testing and tracing must be implemented to curb the risk of transmission, with vaccine availability as another layer of protection," Weingarten said.
The analysis of data from the Georgia school district is based on confirmed COVID-19 cases among roughly 2,600 elementary-school students and 700 staff members who participated in on-campus learning during the 24-day in-person period, according to the CDC.
During that time, the seven-day rolling average of daily virus cases in the surrounding community, in Cobb County just north of Atlanta, increased 300%.
There were 45 confirmed COVID-19 cases during the seven-week period among the more than 3,300 students and teachers included in the analysis, and 31 were attributed to in-school spread.
Of the 31 school-associated cases, 15 involved teacher-to-teacher or teacher-to-student spread.
Furthermore, 18 of the 69 household contacts of these cases later tested positive for the virus, the agency said.
"Educators might play a central role in in-school transmission networks," researchers said in the report.
"Preventing [COVID-19] infections through multi-faceted school mitigation measures and COVID-19 vaccination of educators is a critical component of preventing in-school transmission," the researchers said.