Elinore McCance-Katz, the Trump administration's assistant secretary for mental health and substance use, was urging the CDC to justify its recommendation that Americans stay six feet apart to avoid contracting covid-19 or get rid of it. "I very much hope that CDC will revisit this decision or at least tell us that there is more and stronger data to support this rule than what I have been able to find online," McCance-Katz wrote in a June 2020 memo submitted to the CDC and other health agency leaders. The CDC would keep its six-foot social distance recommendation in place until August 2022. There was little science behind the six-foot rule. "It sort of just appeared, that six feet is going to be the distance," Fauci testified to Congress in a January closed-door hearing, according to a transcribed interview released Friday. Fauci characterized the recommendation as "an empiric decision that wasn't based on data." Francis S. Collins, former director of the National Institutes of Health, also privately testified to Congress in January that he was not aware of evidence behind the social distancing recommendation. The U.S. distancing measure was particularly stringent, as other countries adopted shorter distances; the World Health Organization set a distance of one meter, or slightly more than three feet, which experts concluded was roughly as effective as the six-foot mark at deterring infections, and would have allowed schools to reopen more rapidly.