The American Academy of Pediatrics (AAP) believes that immunizations are the safest and most cost-effective way of preventing disease, disability, and death. We urge parents to make sure that their children are immunized against dangerous childhood diseases since it is always better to prevent a disease than to have to treat it or live with the consequences of having it. On-time vaccination throughout childhood is essential because it helps provide immunity before children are exposed to potentially life-threatening diseases. Vaccines are tested to ensure that they are safe and effective for children to receive at the recommended ages.