Your immune system is improved by natural infection

When a person becomes immune to a disease, it means that his or her body can remember it and has prepared itself to encounter it again. Our immune systems combat all contagious diseases by producing antibodies and memory cells. The antibodies kill the attacking virus or bacterium, and the memory cells remember it for next time. This means that the infection is fought so efficiently that we will not even get sick, if we encounter the same pathogen again. The mechanism is the same in connection with vaccinations. The doctor injects a harmless portion of the disease, often a protein from the surface of the virus particle, into the patient’s body. When we are infected in the normal way, the body gets a fuller image of the virus or bacterium, but vaccines provide more than sufficient information to obtain the desired result, so in practice, it is not an advantage to have the disease.