ABC7 Chicago's Mark Rivera walks you through how to use the COVID-19 vaccine calculator to find your place in line to get the shot. The testing comes as the U.S. stands on the verge of adding a second COVID-19 vaccine to its arsenal as the outbreak descended deeper into its most lethal phase yet, with the nation regularly recording over 3,000 deaths per day. The Food and Drug Administration was evaluating a shot developed by Moderna Inc. and the National Institutes of Health and was expected to give it the green light soon, clearing the way for its use to begin as early as Monday.