Infectious diseases - immunity

The human immune system is the body's natural defence mechanism against disease. It recognises and destroys pathogens inside the body. Pathogens, such as bacteria and viruses, cause damage and disease when they reproduce and grow in number.

However, sometimes, our immune system takes longer or simply cannot identify and neutralise pathogens attacking our body. This is because our body has never been exposed to such pathogens, and therefore does not have defences ready to fight the infection.

Here is where vaccination comes in. Vaccination is the process by which our body creates defences, or antibodies, to fight a pathogen by purposedly being exposed to a non-threatening inactive or dead version of the pathogen. Therefore, vaccination enables the body to respond more quickly to future infection by that pathogen.