The Centers for Disease Control said there's increasing evidence to suggest children and adolescents can efficiently transmit COVID-19.
They point to an investigation where a 13-year-old was the source of an outbreak at a family gathering.
She had been exposed to a confirmed case before the gathering and tested negative via a rapid antigen test.
The teen then shared a house with 13 relatives, and no one wore masks.
She and ten of her relatives developed COVID-19.
There were six relatives who also visited, but stayed outside and maintained social distance.
They did not contract COVID-19.
The CDC says rapid antigen tests have a lower sensitivity, and people should quarantine for 14 days after a known exposure, regardless of test results.