Vaccines work as weapons once they are inside your body; they fight infection diseases. Vaccines are created in labs by dead or altered viruses or bacteria in order to put your body "on alert". Vaccines were made to protect us against deadly diseases and they work because when you receive a vaccine it helps your body creates antibodies. Antibodies are your body's defensive cells that fight off any foreign substances or germs.
A vaccine is a substance that stimulates the Body to produce chemicals that destroy viruses and bacteria. It is made from dead or altered viruses or bacteria. Antibodies are your body's defensive cells that fight off any foreign germs; antibodies are proteins in the blood. Antibodies are proteins in the blood.
A vaccine fools your body's immune system and makes it respond as if you were really infected. You are injected with a harmless version of the bacterium or virus that usually causes the illness: it is either dead, modified or attenuated, so that it cannot attack your body.
But your defender cells still learn what it looks like and start to create defenses. That is why if you ever encounter the real virus or you have been contagious, they will remember, and respond immediately to destroy it.
Sometimes your body can create antibodies on its own. But the diseases you get vaccines for are very dangerous. Most people get very sick and some die before enough antibodies are produced. A vaccine is only a protection if the virus mutes or changes it is going to be necessary to create another vaccine for the new version of the virus that is why the investigation never stops. Nowadays vaccines are mandatory procedures in all around the world because it prevents massive spread of infection diseases.
The vaccines have been a biggest step for the human kind, it is being more than four centuries that human have been fighting against invisible viruses and bacteria even though vaccines are only a protection, they help us fight from different diseases that are very contagious and dangerous, by a simple procedure humans and animals can be protected for infection diseases and prolonging life.