data, school districts around the country are focusing on slowing the spread of covid in the classroom. new york city's mayor says starting september 27th, students attending school in the city will be tested weekly for covid-19. as opposed to biweekly. and in the nation's capital, the mayor getting rid of the testing option and mandating all teachers, staff and child care workers must be vaccinated. >> this applies to d.c. public schools, public charter schools, private schools, parochial schools, and child care facilities. >> reporter: san francisco's mayor, london breed, now at the center of a firestorm over her own mask mandates. mayor breed defiant after she was caught on camera not wearing a mask inside a nightclub. >> i was sitting with my friends, and everyone who came in there was vaccinated. the fact we've turned this into a story about being maskless. no, i'm not going to sip and put my mask on, sip and put my mask