Vaccine Science & Safety

Vaccines are among the most significant achievements in public health. Since 1924, childhood vaccinations have prevented more than 100 million cases of serious disease.

All vaccines used in the United States are required to go through years of extensive safety testing before they are licensed by the US Food and Drug Administration (FDA). FDA and the Centers for Disease Control and Prevention (CDC) work with healthcare professionals to monitor the safety of vaccines, including any adverse events, especially rare events not identified in pre-licensure study trials. There are currently three systems used to monitor the safety of vaccines after they are licensed and used in the US. These systems can monitor known side effects and detect rare side effects that may not have been identified during clinical trials.

One of the three systems used to monitor the post-licensure safety of vaccines in the US is the Vaccine Adverse Event Reporting System (VAERS). VAERS accepts reports from healthcare professionals, vaccine manufacturers, and the general public and receives more than 25,000 reports per year, compared with millions of vaccine doses given to adults.

NFID developed a #ShotOfScience campaign to share tools and resources on the history and science of vaccines. Campaign materials include sample social media posts and animated graphics.

Additional Resources

Centers for Disease Control and Prevention:

Ensuring the Safety of Vaccines in the United States
If You Choose Not to Vaccinate Your Child, Understand the Risks and Responsibilities
The Journey of Your Child’s Vaccine
Understanding MMR Vaccine Safety
Understanding the Vaccine Adverse Event Reporting System (VAERS)
Understanding Thimerosal, Mercury, and Vaccine Safety
Vaccine Information Statements (VIS)


National Academies of Sciences, Engineering, and Medicine:

Vaccines Are Safe