COVID-19 infections.On Tuesday, Canada’s National Advisory Committee on Immunization (NACI) updated its guidance and said vaccines can be safely mixed and matched in most scenarios.The recommendations suggest people who received a first dose of the viral vector-based AstraZeneca vaccine may receive an mRNA shot — Pfizer-BioNTech or Moderna — for their second dose, with the advice of a physician.
NACI recommends mixing AstraZeneca, Pfizer, Moderna COVID-19 vaccines Dr. Zain Chagla, infection control director at St. Joe’s and assistant professor at McMaster University, says although the vaccines trigger an immune response differently, their function is still similar since each makes a viral spike protein to trigger an immune response.“So.