This week, a promising preliminary trial buoyed hopes that a vaccine for the novel coronavirus might be available before 2021, and global stocks rose on the possibility of an accelerated recovery. But according to Dr. Margaret Hamburg, who served as Food and Drug Administration commissioner from 2009 to 2015, every single facet of the convoluted and risky vaccine approval process would have to go perfectly in order for a vaccine to be available this year. Speaking on Walker & Dunlop’s weekly webcast, Hamburg urged optimism, but also a large dosage of caution.