COVID-19 AstraZeneca issues: Pfizer, Moderna are ‘preferred’ for second shot, U.S. travel problem may arise – Yahoo News

National Advisory Committee on Immunization (NACI) is now recommending that individuals who received a single dose of the AstraZeneca COVID-19 vaccine be given an mRNA vaccine, Pfizer-BioNTech or Mod… [+3985 chars]