THE U.S. Food and Drug Administration (FDA) expects to move quickly after a December 10 review of the coronavirus vaccine developed by Pfizer and 20 million Americans could be vaccinated this year, its commissioner has revealed. FDA Commissioner Stephen Hahn declined to give a specific timeline of how long approval of the vaccine developed by Pfizer and BioNTech would take but said that he hoped there would be a decision by the regulator in December. As soon as the FDA approves a vaccine, "I will be first in line and I will encourage my family to take this vaccine," Hahn…