The Food and Drug Administration refused to review Moderna’s application for its new mRNA flu vaccine — a move the pharma giant’s’s president Dr. Stephen Hoge said left him in “complete shock.” In an exclusive interview with The Post, Hoge said he was “completely surprised and honestly pretty confused” after receiving a letter from Dr. Vinay Prasad, the FDA’s vaccine director, who said that the company’s application didn’t contain an “adequate and well-controlled” trial of its new vaccine.