This 2020 electron microscope made available by the U.S. Centers for Disease Control and Prevention image shows the spherical coronavirus particles from the first U.S. case of COVID-19. On Monday, May 4, 2020, New York City health authorities issued an alert to doctors about severe inflammatory condition possibly linked with COVID-19 has been found in a cluster of U.S. children in New York City after first being reported in Europe. (C.S. Goldsmith, A. Tamin/CDC via AP)(C.S. Goldsmith, A. Tamin/AP)