Your immune system is like the search and destroy unit of your body. It protects your body from disease by seeking out and killing infecting cells.

The first line of defence for your immune system is the innate immune system. Your skin and saliva are facets of this part of your immune system.

The second part to your immune system is the acquired immune system. If pathogen cells make it past your innate immune system, the acquired immune system will kick in. Acquired immune systems need to have seen the infectious agent before it attacks it which is why babies and infants are so vulnerable to infection.

Vaccinations and immunisations work with the acquired immune system as they usually deliver the very antigen they are guarding against. This way your immune system will recognise it when it really does invade.

For more information on your immune system, click here.