Question: How do we become emmune from diseases?

Julie Greensmith answered on 20 Jun 2011:

The human body has a bunch of cells called the “immune system”. These cells can recognise bits of invading germs called pathogens through some proteins called antibodies. Different invaders need different antibodies to be produced so that the body can fight the germs. If we are exposed to a pathogen, the immune system tries lots of different types of antibodies until the right one is found to help the immune system get rid of the germs. Its like finding the right key for a lock. Once the right key is found, it is kept in immune memory. If we get attacked by that germ again, we have the right antibody to fight it and so we become “immune” to that germ.