On average, adults catch more than 150 colds throughout their lives. Even with similar symptoms, the cause could be different each time. Common colds are caused by at least 8 different families of virus, each of which can have its own subtypes. How can so many different viruses cause the same illness? And is a cure even possible? Explore the two main strategies we employ to fight viruses. This TED-Ed lesson was directed by Anton Bogaty, narrated by George Zaidan and the music is by Nikola Radivojevic.