History of Vaccine Safety

Perhaps the greatest success story in public health is the reduction of infectious diseases resulting from the use of vaccines. Routine immunization has eradicated smallpox from the globe and led to the near elimination of wild polio virus.

Vaccines have reduced some preventable infectious diseases to an all-time low, and now few people experience the devastating effects of measles, pertussis, and other illnesses. Prior to approval by the Food and Drug Administration (FDA), vaccines are tested extensively by scientists to ensure they are effective and safe.

Vaccines are the best defense we have against infectious diseases; however, no vaccine is 100% safe or effective. Differences in the way individual immune systems react to a vaccine account for rare occasions when people are not protected following immunization or when they experience side effects.

As the incidence of infectious diseases continues to decline, some people have become less interested in the consequences of preventable illnesses like diphtheria and tetanus. Instead, they have become increasingly concerned about the risks associated with vaccines. After all, vaccines are given to healthy individuals, many of whom are children, and therefore a high standard of safety is required.

Since vaccination is such a common and memorable event, any illness following immunization may be attributed to the vaccine. While some of these reactions may be caused by the vaccine, many of them are unrelated events that occur after vaccination by coincidence. Therefore, the scientific research that attempts to distinguish true vaccine side effects from unrelated, chance occurrences is crucial. This knowledge is necessary to maintain public confidence in immunization programs.

As science continues to advance, we strive to develop safer vaccines and improve delivery to protect ourselves against disease more effectively. This overview focuses on vaccine research, how vaccines are licensed, how safety is monitored, and how risks are communicated to the public