As states roll back masking requirements for students, a new study shows that masks helped cut Covid-19 infections in public K-12 schools that required them in the fall.

The study comes from a partnership between the US Centers for Disease Control and the Arkansas Department of Health. Investigators looked at Covid-19 infections in Arkansas schools over a period of about seven weeks from August to October 2021.

Overall, schools that required masks had 23% fewer Covid-19 cases on average than those that didn’t.

The research compared Covid-19 infections in 233 public school districts. Among these, 30% required students and staff to mask up, 21% required masks part of the time, and 48% didn’t have mask requirements.

Compared with districts that didn’t require masks, districts that did had 22% fewer Covid-19 cases among students in kindergarten through fifth grade; 31% fewer cases among students in grades six through eight; and 32% fewer cases among students in grades nine through 12.

Overall, vaccination coverage for students and staff ranged from 13.5% at the start of the study to 18.6% by the end.

Districts with higher vaccination coverage — with more than 40% of students and staff vaccinated — combined with mask requirements, had 38% fewer Covid-19 cases compared with districts without mask requirements.

The data was collected before the Omicron variant became prevalent in the United States.

See the full article from CNN Health here.