Jubilation at the introduction of Covid-19 vaccines is giving way to debates about boosters and fears of breakthrough infections. And people are understandably confused about how vaccines work. How could they possibly help us fight a virus years or even decades in the future? Infectious disease expert Monica Gandhi of the University of California, San Francisco explains how this seemingly magical process works – with special B and T cells that hide away in your lymph nodes and bone marrow, ready to respond when needed. Understanding how the immune system works can bring some understanding to today’s outrage-filled debates about Covid-19 vaccines – and it’s fascinating to boot.

“Follow the Science" is produced, written, and hosted by Faye Flam, with funding by the Society for Professional Journalists. Today’s episode was edited by Seth Gliksman with music by Kyle Imperatore. If you’d like to hear more "Follow the Science," please like, follow, and subscribe!