Vaccines Are Very Safe - National Immunization Awareness Month
As part of National Immunization Awareness Month, it's important to remember that vaccines are safe. Some parents have questions about vaccine safety. If you do, speak with your primary care physician or your local health department about your concerns.
Here are some quick facts:
• Vaccines are thoroughly tested before licensing and carefully monitored after they are licensed to ensure that they are
• Vaccines are among the safest and most cost-effective ways to prevent disease. They not only protect vaccinated
individuals but also help protect entire communities by preventing and reducing the spread of infectious diseases
• Currently the U.S. has the safest, most effective vaccine supply in its history. The U.S. longstanding vaccine safety
system ensures that vaccines are as safe as possible. As new information and science become available, this system
will continue to be updated and improved.
• All vaccines used in the United States are required to go through years of extensive safety testing before they are
licensed by the U.S. Food and Drug Administration (FDA).
• FDA and CDC work with health care providers throughout the United States to monitor the safety of vaccines, including
for any adverse events, especially rare events not identified in pre-licensure study trials.
• There are three systems used to monitor the safety of vaccines after they are licensed and being used in the U.S.
These systems can monitor side effects already known to be caused by vaccines, as well as detect rare side effects
that were not identified during a vaccine’s clinical trials.
• One of the three systems used to monitor the safety of vaccines after they are licensed and used in the U.S. is called
the Vaccine Adverse Event Reporting System (VAERS). VAERS accepts reports from health professionals, vaccine
manufacturers, and the general public and receives about 30,000 U.S. reports per year, compared with millions of
doses given to adults.
• Many types of adverse events occur after vaccination. About 85 to 90 percent of the reports describe mild adverse
events such as fever, local reactions and mild irritability. The remaining reports reflect serious adverse events involving
life-threatening conditions, hospitalization, permanent disability, or death, which may or may not have been caused by