We know that a disease that is apparently under control can suddenly return, because we have seen it happen, in countries like Japan, Australia, and Sweden. Here is an example from Japan. In 1974, about 80% of Japanese children were getting pertussis (whooping cough) vaccine. That year there were only 393 cases of whooping cough in the entire country, and not a single pertussis-related death. Then immunization rates began to drop, until only about 10% of children were being vaccinated. In 1979, more than 13,000 people got whooping cough and 41 died. When routine vaccination was resumed, the disease numbers dropped again.
The chances of your child getting a case of measles or chickenpox or whooping cough might be quite low today. But vaccinations are not just for protecting ourselves, and are not just for today. They also protect the people around us (some of whom may be unable to get certain vaccines, or might have failed to respond to a vaccine, or might be susceptible for other reasons). And they also protect our children’s children and their children by keeping diseases that we have almost defeated from making a comeback. What would happen if we stopped vaccinations? We could soon find ourselves battling epidemics of diseases we thought we had conquered decades ago.