For most people, the risk of getting sick increases with age. Dr. Mosley wants to find out how we've become so much better at fighting infection, and he's looking for the secrets to keeping our bodies healthy on the inside, starting with the immune system.

邁克爾莫斯利博士試著發現維持健康的秘密，他檢視人們讓身體更能抵抗感染和疾病的方法。