BOSTON (CBS) — Gov. Charlie Baker’s administration is looking to mandate masks for everyone in K-12 public schools through Oct. 1 as the Delta variant causes a rise in COVID cases. Education Commissioner Jeffrey Riley is asking the Board of Elementary and Secondary Education to give him the power to institute the mask mandate “to provide time for more students and educators to get vaccinated.”

Once the proposed mandate ends on Oct. 1, vaccinated students and staff at middle and high schools would no longer have to wear masks if at least 80% of students and staff in the building are vaccinated. Any unvaccinated people in schools would still need to mask up.

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“While Massachusetts leads the nation in vaccination rates, we are seeing a recent rise in COVID-19 cases because we still need more people to get vaccinated,” Baker said in a statement. “This step will increase vaccinations among our students and school staff and ensure that we have a safe school reopening.”

Students unable to wear a mask due to medical or behavioral needs would be exempt. It applies indoors to those 5 years old and above.

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Baker has previously resisted a mask mandate in schools, despite CDC recommendations that everyone in schools be masked regardless of vaccination status. State guidance had suggested no mask mandates for vaccinated students, while strongly recommending masks for in grades 6 and below who were not yet eligible to be vaccinated.

Boston and some other cities and towns have already said they’ll institute mask mandates in the fall.

“As students and staff prepare to return to school full-time, in-person, our priority is on a smooth reopening,” Commissioner Riley said. “With cases rising, this mask mandate will provide one more measure to support the health and safety of our students and staff this fall.”

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The policy will be revisited based on public health data, Riley said. Staff