To understand how vaccines work, we first need to understand how our body fights infections. We have a very smart system called the immune system.
The immune system works by producing immune cells that target and kill infections.
The first time the body encounters a germ, it can take several days
to produce the right immune cells to kill the infection. After the infection, the immune system remembers what it learned about how to protect the body against that disease.
If we encounter the same germ again after the first exposure, our immune system will know how to react immediately, and this time we don’t have to wait several days to get rid of the germ. The germ simply don’t have the time to multiply in our body because our immune system works so quickly.
Vaccines work by imitating an infection. When injected with vaccine, the “fake” virus will trigger the same immune response in our body.
But because this “fake” virus does not multiply, it won’t actually cause any illnesses. The whole idea is to “teach” our immune system how to react when it encounters the real virus in the future.