ABC News Turn on desktop notifications for breaking stories about interest? OffOn Most people won't experience allergic reactions to the vaccine, experts insist. • 8 min read Member of FDA advisory committee discusses COVID-19 vaccine authorization Dr. Ofer Levy of Boston Children's Hospital discusses Pfizer's vaccine emergency authorization and the plans for Moderna's vaccine.Bloomberg via Getty Images, FILE The Food and Drug Administration late Friday authorized Pfizer'sCOVID-19 vaccine for people ages 16 and up, but warned that those with known severe allergic reactions to any of the vaccine's components should avoid taking it. But this begs the question -- what is in the vaccine?