Emergency Preparedness for 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.

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Examples of Past Vaccine Safety Emergency Responses