This 2020 electron microscope image made available by the U.S. Centers for Disease Control and Prevention shows the spherical particles of the new coronavirus, colorized blue, from the first U.S. case of COVID-19. The Canadian Association of Emergency Physicians is calling on its doctors to protect the limited supply of certain sedatives and pain killers needed to ventilate patients. THE CANADIAN PRESS/Hannah A. Bullock, Azaibi Tamin/CDC via AP