• Currently, the United States has the safest vaccine supply in its history. • The United States’ long-standing vaccine safety system ensures that vaccines are as safe as possible. It detects problems rapidly and allows us to respond. As new information and science become available, this system is, and will continue to be, updated and improved. • The U.S. Food and Drug Administration (FDA) ensures the safety, effectiveness, and availability of vaccines for the United States. Before the FDA licenses (approves) a vaccine, the vaccine is tested extensively by its manufacturer. FDA scientists and medical professionals carefully evaluate all the available information about the vaccine to determine its safety and effectiveness. • Most common side effects of a vaccine are identified in studies before the vaccine is licensed. Some adverse events are so rare, however, that they may not be detected in these studies. Therefore, the U.S. vaccine safety monitoring system continuously monitors for adverse events (possible side effects) after a vaccine is licensed. When millions of people receive a vaccine, less common side effects that were not identified earlier may show up. vacsafe-ensuring-color-office.pdf

Stephen B. Thacker CDC Library collection