Most vaccines contain a weakened or dead disease germ. Other vaccines use inactivated toxins. Some of the bacteria that cause disease do so by producing toxins that invade the bloodstream. Next - The body makes antibodies to fight the weakened or dead germs in the vaccine. Then - These antibodies practice on the weak germs so when the real, strong disease germs which can be lurking all around invade the child s body, the antibodies will know how to destroy them and the child will not become ill.
Most vaccines don t cause the diseases that are usually caused by viruses and bacteria.
Finally - Protective antibodies stay on guard in the child s body to safeguard it from the real disease germs. After exposure to a live, weakened, or dead germ, the antibodies or memory cells fight infectious diseases and usually stay in a person s immune system for a lifetime. This protects a person from getting sick again. This protection is called immunity. It is true that newborn babies are immune to many diseases because they have antibodies they got from their mothers.