1. TEDMED: Let’s start with the basics. What is a virus?
A virus is a very tiny particle of RNA or DNA genetic code protected by an outer protein wrapper.
2. TEDMED: How common are viruses?
Viruses are everywhere. It’s amazing to realize that if you add them all up, all the viruses in the world weigh more than all the living matter in the world – including all of the plants, animals and bacteria. 10% of the human genome is derived from virus DNA. The Earth truly is a “virus planet!”
3. TEDMED: Why is it so hard to stop a virus from spreading?
Because virus particles are so incredibly small, billions can float on tiny droplets in the air from just one cough.





