Sao Paulo began a mass COVID-19 testing program on Thursday for public school employees and students, as Brazil’s largest city seeks to edge back to normalcy even as Brazil continues to report tens of thousands of additional coronavirus cases daily. The city is planning to test some 777,000 people, including students and teachers, in three phases, a move officials hope will allow the megalopolis to restart in-person classes. In the first phase, 193,000 people will be tested. Sao Paulo is not alone in relying on tests as a key part of its strategy to gets schools back up and running. Major school districts in the United States and elsewhere are relying on similar strategies. But the effort in Brazil is among the most daunting. Sao Paulo has over 12 million people within city limits. Almost 13,000 Paulistas, as city residents are known, have died from the virus. Schools have been closed since March 23. In the first phase of the testing program, workers from some 468 public health clinics will fan out over the city to administer tests over the course of 15 days.