Right now, without any conscious effort from you, an enormous distributed defence network is identifying and destroying threats inside your body. We look at how your immune system tells self from invader, why it remembers infections for decades, and what happens when this beautifully engineered system turns on the body it is meant to protect.

You'll come away understanding the difference between innate and adaptive immunity, why boosting your immune system is mostly a marketing phrase, and how allergies and autoimmune disease are the same machinery misfiring.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Immunobiology (Janeway); British Society for Immunology public resources; Nature Reviews Immunology.