An adult and child wear protective face masks in the Bethesda Arcade in Central Park on July 29, 2020, in New York City. | Noam Galai/Getty Images

Several new studies are deepening our understanding of infection and transmission in kids, but there’s still a lot we don’t know.

In mid-June, a sleepaway camp in Georgia opened for its first camp session of the summer, welcoming 363 campers and 234 staffers and trainees back for what was supposed to be a fun summer outdoors. The camp followed most of the Centers for Disease Control and Prevention (CDC) guidelines, including keeping campers in cabin groups as much as possible. But the campers were not required to wear masks for camp activities, including singing and cheering.

Six days in, a teenage staff member left camp after developing chills, and tested positive for Covid-19. Eventually, 49 percent