With the advent of vaccines, these deaths have been nearly eliminated in the United States. Immunizations are extremely safe, thanks to advancements in medical research and ongoing review by doctors, researchers, and public health officials. Vaccines undergo rigorous testing before they are ever approved for use. Moreover, testing and evaluation continues as long as a vaccine is in use. If safety concerns regarding the vaccine arise, immediate steps are taken to research whether the vaccine causes any adverse events.
Children are far more likely to be harmed by serious infectious diseases than by immunizations.
The weight of scientific evidence shows that serious adverse reactions to vaccines are exceptionally rare. Conversely, we know that diseases that can be prevented by vaccines can and do cause long-term disability and even death. The younger children are when they contract an infectious disease, the more likely it is that they will become seriously ill. Immunizations help children whose immune systems are not yet fully developed fend off diseases, without causing the devastating side effects that natural infection can cause. People who are not immunized increase the chance that others will get the disease.