Professor of Infectious Diseases Dr. William Schaffner says although Pfizer’s COVID vaccine has “a tiny little piece of the COVID virus in it,” it is not a live virus vaccine. CoronavirusCOVID-19COVID19COVID19 immune systemdiseaseExpertimmune systemIMMUNITYInfectiousinfectious disease expertPfizerSharesVaccinevaccine concernsvideoVITAMINvlogwhat to knowYouTube