In this MD Newsline exclusive interview with Dr. Tom Shimabukuro of the CDC’s Immunization Safety Office, we discuss how the CDC monitors vaccine safety.
How does the CDC monitor vaccine safety?
Dr. Tom Shimabukuro:
“At the CDC, we have several systems that help us monitor the safety of vaccines. The first system is called “v-safe.” It was developed for COVID-19 vaccination, and it’s a voluntary self-enrollment program. The program uses text messaging with links to secure surveys to ask people about their post-vaccination experiences. V-safe is still active, and we encourage people to register and use v-safe.
We also encourage healthcare providers to share v-safe with their patients. Additionally, with the COVID-19 vaccines now available to children, it’s important to note that parents can enroll in v-safe on behalf of their children.
With v-safe, patients can send us information about local injection site reactions, systemic reactions, and health-impact events post-vaccination. Such events might include how the vaccine impacts their ability to perform daily activities or go to work or school, or even if they seek healthcare for their symptoms.
So, this is one system that we use to monitor vaccine safety, and we can start monitoring vaccine safety as soon as an individual has been vaccinated. It’s given us early information on the basic safety profile of the vaccine.
We also have a system called the Vaccine Adverse Event Reporting System (VAERS). It’s familiar to a lot of healthcare providers, especially pediatricians. VAERS depends on patients, parents, healthcare providers, and others to send reports of adverse events following immunization to the VAERS program. This program is also very responsive and has given us early data to characterize the safety profiles of these vaccines.
VAERS does have some limitations. We have a limited amount of data from people who have chosen to send reports to VAERS, and some of the information can be incomplete. Because of these limitations, we’re generally not able to assess from VAERS data alone whether or not a vaccine caused an adverse event.
Another system is the Vaccine Safety Datalink. This system is a large database integrated with several large healthcare organizations. We partner with these organizations to use the electronic health records at these sites to conduct vaccine safety monitoring and research. With this system, we have complete or near-complete information on these patients and can generate rates, establish risk, and assess causality. For COVID-19, we’ve been able to do weekly sequential monitoring as the data become available to us.
Finally, the last system is the Clinical Immunization Safety Assessment Project (CISA). This is the CDC’s clinical research group in the Immunization Safety Office. We do detailed clinical case reviews and consult with healthcare providers on their patients. We also help develop case definitions, determine if a diagnosis is correct, develop clinical guidance, and make vaccine reccommendations.”
Responses have been condensed and lightly edited.