(Reuters) – The U.S. Centers for Disease Control and Prevention on Friday updated its guidance to help reopen schools in the fall, including recommending masking indoors for everyone who is not fully vaccinated and three feet of distance within classrooms.

The CDC in its latest guidance said all kindergarten through grade 12 schools in the United States should continue to mandate wearing masks indoors by all individuals who are not fully vaccinated.

The agency said that if localities decide to remove prevention strategies in schools based on local conditions, they should remove them one at a time. Schools should monitor closely for increases in COVID-19 cases before removing the next prevention strategy.

“Because of the importance of in-person learning, schools where not everyone is fully vaccinated should implement physical distancing to the extent possible within their structures, but should not exclude students from in-person learning to keep a minimum distance requirement,” the new guidance said.

A study by the CDC also released on Friday showed that half of unvaccinated adolescents and parents of unvaccinated adolescents reported being uncertain about getting a COVID-19 vaccine, or did not intend to get one at all.

(Reporting by Mrinalika Roy in Bengaluru; Editing by Dan Grebler)