IMMUNE SYSTEM
One of the most common diease in the world is known as influenza, commonly known as the flu. The flu is one of most cunning dieases it's almost changing and finding a way to ruin your body. In today's world there are only 3 types of the flu, but there will be more to be made since the flu is constantly making new strands of itself.
The way you can receive the flu is by breathing it in or touching the virus and putting it in your mouth. The first sysmptom you receive from influenza is body aches and chills. When you start receiving those symptoms your immune system responds by sending antibodies. An antibody is like your first line of defense for your body fighting the influenze, if it fails then your symptoms start getting worse. You start getting headaches, sore throat, vomiting and maybe diarrhea but before all that can happen your body has a second line of defense. This second line of defense towards killing the virus in your body is known as the 'killer' cells. These cells use their memory from past viruses to produce antibodies that are stonrger and know how to deal with the virus at hand. Once those antidodies defeat the influenze your body just goes back to normal and you don't have to worry about any long term effects because influenze doesn't have any.