How vaccines train your immune system
The short answer
A vaccine lets your immune system meet a harmless copy of a germ, learn its shape and remember it, so the real germ meets a fast response.
0:28The human bodyIntermediatevaccinesimmune systemantibodies
Chapters and transcript
- 0:00
A vaccine shows your body a harmless copy
It contains a weakened or inactive germ, a piece of one, or the recipe for making that piece.
- 0:07
Your immune cells learn its shape
Immune cells make antibodies that fit the germ’s shape, like keys cut for one lock.
- 0:14
Memory cells stay on guard
Long after the vaccine has gone, memory cells remember that shape.
- 0:21
The real germ meets a fast response
If the real germ arrives, the body knows it at once, so it fights back sooner and harder. The chart in the video is an illustration, not measured data.