https://www.siliconvalley.com/2022/01/06/cdc-updates-covid-prevention-guidance-for-k-12-schools/

(CNN) — The US Centers for Disease Control and Prevention updated its guidance for Covid-19 prevention in K-12 schools on Thursday, aligning the recommendations with the agency’s recently updated Covid-19 quarantine and isolation guidelines for the general public. It also expands its recommendations for screening testing and urges canceling or going virtual with some extracurricular and sports activities in order to protect in-person learning.

The new K-12 school recommendations say children who have not been fully vaccinated and are exposed to the coronavirus should quarantine for at least five days after their last close contact with a person who has Covid-19. Adults who are not vaccinated against Covid-19 or who have not received a booster shot are advised to follow this recommendation, too.