FILE - Katie Lucey administers a COVID-19 test on her son Maguire at a PCR and Rapid Antigen COVID-19 coronavirus test pop up on Wall Street in New York on Thursday, Dec. 16, 2021. U.S. health officials are endorsing ‘test-to-stay’ policies that will allow close contacts of infected students to remain in classrooms. The Centers for Disease Control and Prevention on Friday, Dec. 17, decided to more firmly embrace the approach, after research of such policies in the Chicago and Los Angeles areas found COVID-19 infections did not increase when schools switched to test-to-stay. (AP Photo/Ted Shaffrey)