How Do Messenger RNA (mRNA) Vaccines Work?

An infographic describing how mRNA vaccines work. The text below fully describes the graphic content.
Credit: Cody Shipman, CoVPN

mRNA vaccines give your body the information needed to defend against a virus.

  1. mRNA has instructions for making the spike protein from SARS-CoV-2.
  2. mRNA enters a human muscle cell through an injection.
  3. mRNA in the cell delivers the Instructions to make the spike protein. It lasts about 24 hrs.
  4. Cell makes spike protein and displays it on the surface for about 3 days.
  5. Immune system sees the spike protein, recognizes it as foreign, and creates an immune response to prevent disease.

How Many Doses Are Needed?

These vaccines require 2 doses to get the most benefit.

  • 1 DOSE = about 50% protection
  • 2 DOSES = about 95% protection

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Content last reviewed on May 12, 2021