What you need to know to maintain a healthy immune system

Your immune system is a network of cells and proteins that defends your body against infection. It keeps a record of every germ it has ever defeated so it can recognise and destroy the germ quickly if it re-enters your body. The healthier your immune system, the less severely cold and flu symptoms will affect you, and the faster your symptoms will disappear.

Humans have three types of immunity:

Innate immunity is a type of general protection that everyone is born with. For example, your skin and immune system are built-in defences against threats.

Adaptive immunity develops throughout your life when you’re exposed to diseases or immunised against them. For example, chicken pox usually only affects a person once.

Passive immunity is borrowed from another source and lasts for a limited time. For example, the antibodies in a mother’s breastmilk give her baby temporary immunity to diseases the mother has been exposed to.