The Centers for Disease Control and Prevention recommended Tuesday that all students in kindergarten through 12th grade should wear masks when they return to classrooms for the new school year.
The newly issued CDC guideline includes youngsters who have already been vaccinated.
CDC Director Rochelle P. Walensky urged all schools reopen to in-person learning in the fall, but with proper safety protocols — and that now includes masks.
"CDC recommends that everyone in K-12 schools wear a mask indoors, including teachers, staff, students and visitors regardless of vaccination status," she told reporters.
President Joe Biden said he understands the masking recommendation will be a disappointment to many children, parents, teachers and school staff.
"Today, the CDC also reaffirmed that we can safely reopen schools this fall — full time," he said in a statement. "Masking students is inconvenient, I know, but will allow them to learn and be with their classmates with the best available protection."
Last week, the American Academy of Pediatrics also recommended that children 2 and older should wear masks when they go back to school.
Children 12 and older are now eligible to be vaccinated against COVID-19.
Walensky on Tuesday also confirmed earlier reports that the Biden administration is now recommending indoor mask use for anyone in areas of high transmission.
The CDC director acknowledged that these new masking recommendations will not be welcomed by millions of Americans who believed the nation had gotten past the virus.
"Not only are people tired, they're frustrated," she said. "This was not something that we took lightly and something that I know weighs heavily with me and with all America."
More than 163 million Americans have been fully vaccinated, according to CDC data Tuesday, though public health officials are concerned that the sizable unvaccinated population is contributing to rising cases of the virus' delta variant.
When asked if CDC would ever call for mandatory vaccinations, Walensky said those are decisions best left for private businesses and local governments. She also acknowledged that mandates could fall on deaf ears.
"We're encouraging really any activities that would motivate further vaccination," she said. "Not all communities are going to be be responsive to a mandate in the same way."
The president said more vaccination is the only way Americans will finally vanquish the virus and take off their masks for the last time.
"Most importantly, today’s announcement also makes clear that the most important protection we have against the Delta variant is to get vaccinated," he said. "Although most U.S. adults are vaccinated, too many are not. While we have seen an increase in vaccinations in recent days, we still need to do better."