Top White House officials pressured the Centers for Disease Control and Prevention this summer to play down the risk of sending children back to school, a strikingly political intervention in one of the most sensitive public health debates of the pandemic, according to documents and interviews with current and former government officials.

As part of their behind-the-scenes effort, White House officials also tried to circumvent the C.D.C. in a search for alternate data showing that the pandemic was weakening and posed little danger to children…

In another instance, Dr. Birx took a direct role in an effort to push the C.D.C. to incorporate work from a little-known agency inside the Department of Health and Human Services, the Substance Abuse and Mental Health Services Administration.

The document worked on by the mental health agency struck a different tone from the cautious approach being proposed by the C.D.C., warning that school closures would have a long-term effect on the mental health of children. It said that “very few reports of children being the primary source of Covid-19 transmission among family members have emerged” and asserted that children who were asymptomatic “are unlikely to spread the virus.”