Fun Facts About the Immune System You Didn’t Know

Your body makes about a billion new immune cells daily.
Most of your immune system resides in your gut, not blood.
Sneezing and fever are carefully controlled immune tactics.
Your immune system can recognize over a trillion unique patterns.
Some immune cells live for decades, quietly guarding you.
Every fingerprint of infection leaves a trace in your immune memory.
Space travel temporarily weakens immunity.
Exercise and laughter can both boost natural killer cell activity.
Immune cells “talk” using molecules smaller than dust particles.
You fight off infections daily without even knowing it.