$PFE, $BNTX Dose First Participants in the U.S. as Part of Global COVID-19 mRNA Vaccine Development Program    #Pfizer      #BioNTech    #mRNA   #Coronavirus    #COVID19     #CoronavirusPandemic    #COVID19Pandemic  #CoronavirusOutbreak    https://t.co/mYTbuxcpGk https://t.co/noJBvDlBt9