A contact-tracing study published this month by the journal Pediatrics found "no instances of child-to-adult transmission" of Covid-19 among more than 90,000 students and staff in 11 North Carolina school districts who attended school in-person for 9 weeks during August to October of 2020. The schools had social distancing and mask requirements and operated under a hybrid model in which "50% of children received in-person instruction Monday and Tuesday; 50% Thursday and Friday; and Wednesday was used for cleaning the building during remote instruction for all students." The study found that 32 of these 90,000 people caught C-19 in school, while 773 caught C-19 while out of school. "Due to confidentiality concerns," the researchers "were not able to analyze incidence of child-to-child or adult-to- child transmission" or "determine the relative effectiveness of any specific school policies."