Emergency Preparedness and Vaccine Safety

CDC’s Immunization Safety Office (ISO) prepares for emergencies by ensuring that robust systems are in place to rapidly monitor vaccine safety in the event of an emergency vaccination program.

During an emergency involving mass vaccination, monitoring vaccine safety is important because:

  • Large numbers of vaccines might be given in a short period of time, and therefore more adverse events (possible side effects) might be reported to the Vaccine Adverse Event Reporting System (VAERS).
  • Public awareness of vaccination programs during an emergency might stimulate reporting to VAERS resulting in higher volume reporting than during non-emergency situations
  • The vaccines being used might be new, so safety data would be limited.  In this situation it will be important to closely monitor safety to detect unexpected or concerning patterns.

Vaccine Safety Tools in an Emergency

  • VAERS accepts vaccine adverse event reports from patients, parents, healthcare professionals, vaccine manufacturers and others.  CDC and FDA scientists review reports and use statistical techniques to detect unusual or unexpected patterns that might indicate a vaccine safety problem.
  • The Vaccine Safety Datalink (VSD) project gathers information on vaccines given to members of certain health care organizations around the country. A system called rapid cycle analysis allows CDC to address vaccine-associated health problems very quickly.
  • Vaccine Safety Coordinators positioned in 62 health departments in states, territories, large urban areas and freely associated states carry out vaccine safety and emergency preparedness activities while coordinating with CDC.

Examples of Past Vaccine Safety Emergency Responses

In response to concern about smallpox possibly being used as a biological weapon, President George W. Bush launched the National Smallpox Pre-Event Vaccination Program on December 13, 2002. Studying the vaccine’s safety was an essential aspect of the program. A system for passive surveillance (a scientific term which means that you can choose if you report possible side effects) was built from VAERS.

For more information, read the special supplement of the journal Clinical Infectious Diseases, entitled “Posteradication Vaccination Against Smallpoxexternal icon.”

ISO played a major role in the H1N1 influenza pandemic of 2009 and 2010. CDC utilized VAERS and VSD to monitor the safety of the H1N1 influenza vaccine. In addition, the Department of Health and Human Services established the H1N1 Vaccine Safety Risk Assessment Working Group to review 2009 H1N1 vaccine safety data as it accumulated.

For more information, read The 2009 H1N1 Pandemic: Summary Highlights, April 2009-April 2010.