Every year since 1995 the Centers for Disease Control and Prevention (CDC), American Academy of Pediatrics (AAP), and American Academy of Family Physicians (AAFP) have endorsed annual childhood and adult immunization schedules. Prior to 1995, these groups updated the immunization schedule every few years as needed. 

This timeline shows what year a vaccine first became available; however, individuals cannot assume they received a vaccine based on their age and the availability of a vaccine due to changes in recommendations, vaccine availability, and individual healthcare decision making.

Find out about studies that have estimated the impact of vaccines in the U.S.

Many scientists have made discoveries important to the development of vaccines. This page honors scientists who have died over the past several years whose work contributed to the science of vaccines.