U.S. coronavirus cases have surpassed 15 million as the country enters what many are calling a "dark" period. But help may soon be on the way as the FDA is set to consider Pfizer's application for emergency use of its coronavirus vaccine. CBS News correspondents Charlie D'Agata and Adriana Diaz have the latest on the race for a vaccine, then Dr. Amesh Adalja, an infectious disease expert and senior fellow at Johns Hopkins University's Bloomberg School of Public Health, joins CBSN to break down the latest.