State Health Director Dr. Betsey Tilson on protective measures in schools to the North Carolina Board of Education on Thursday. Tilson said state health officials have compared the rate of COVID-19 clusters in North Carolina schools without mask mandates to those that require masks. They found masks significantly reduce the risk of clusters.
Among the schools studied:
- 3 counties without mask mandates in schools saw an average of 17.2 clusters per 100 schools
- 35 counties with consistent mask mandates did not report a school cluster
- 54 counties with consistent mask mandates saw an average of 6.9 clusters per 100 schools
- 8 counties that reported mask mandates and changed school mask mandates during the study period were excluded
Tilson also cited a that showed schools without a mass requirement are "3 1/2 times more likely to have COVID outbreaks than schools that started the year without a mask requirement."
State Board of Education Member Amy White asked whether child hospitalization and death rates were higher in counties without mask mandates.
Tilson said those rates were too low to provide reliable data, but COVID-19 rates among children do also affect transmission to adults.
Currently, five counties in North Carolina have mask-optional policies.

Under a recent state law, school boards must vote every 30 days on whether to continue mask requirements.
There have been over 1.4 million total cases of COVID-19 in North Carolina since the beginning of the pandemic, according to the latest data from state health officials.
As of Thursday, 54% of the total state population is fully vaccinated against COVID-19.
¼ª²ÊÍøÍøÕ¾'s Laura Pellicer contributed to this report.