The CDC emphasizes, “Because of vaccines, some diseases (like polio and diphtheria) are becoming rare in the United States. Vaccinations can prevent certain deadly diseases in infants, children, teens, adults, and travelers of all ages”.
How do vaccines work?
Vaccines help form immunity by mocking an infection. This type of infection, though, almost never causes an illness. It does, however, cause the immune system to build very specific white blood cells and antibodies. Sometimes, after getting a vaccine, the imitation infection can cause light symptoms, such as a fever. These minor symptoms are to be expected as the body builds immunity. Once the imitation infection goes away, the body is left with a stockpile of “memory” white blood cells that will remember how to fight off that disease in the future.
Vaccines prevent diseases that can be dangerous, or even deadly. It is always better to prevent a disease than to treat it after it occurs!
Newborn babies are immune to many diseases because they have antibodies they got from their mothers. However, this immunity goes away during the first year of life (CDC).