How Sweden wasted a ‘rare opportunity’ to study coronavirus in schools | Science | AAAS "In the town of Skellefteå, a teacher died and 18 of 76 staff tested positive at a school with about 500 students in preschool through ninth grade. The school closed for 2 weeks because so many staff were sick ... At least two staff members at other schools have died" In Israel, schools closed for a single case, and close contacts of every infected individual were tested and quarantined, Aflalo says. By mid-June, 503 students and 167 staff had been infected, and 355 schools had closed temporarily. So in Israel none of the 167 staff members who got covid got it from a student? None of the teachers/staff in Sweden who died or just got infected got it from a student? How did they come to that conclusion?