To answer this, TED-Ed developed this animated video which explains how the immune system works. It also shows how, using this knowledge, scientists found ways to help our bodies protect us from infectious diseases.
This is not the only TED talk explaining immunisation. In a fascinating TEDmed talk on the value of herd immunity, Prof Adam Finn of the University of Bristol, explains the history of whooping cough outbreaks to illustrate the danger of complacency.
“People need to understand why vaccines are important not just when a disease is common but also when it has become rare,” according to Professor Finn.
*Warning* There’s a video of a child who had whooping cough around the 1-minute mark which some may find distressing
Do you have a favourite YouTube video about vaccines?