The COVID pandemic drew new attention to the system the U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) use to monitor how vaccines work. The Vaccine Adverse Event Reporting System (VAERS) takes reports from members of the public as well as medical professionals and patients. Due in part to the broad-based system of collection, VAERS will sweep in cases where people report medical complications and conditions that may ultimately be found unrelated to vaccines they received. There’s been notable concern about members of the public misinterpreting VAERS reports and spreading misinformation about vaccines.
Established in 1990, VAERS can serve as an early warning system, with its wide reach helping doctors and researchers more easily pick up signals of rare side effects of vaccines, such as anaphylaxis and Guillain-Barré Syndrome (GBS). VAERS is “good at detecting unusual or unexpected patterns of reporting that might indicate possible safety problems that need a closer look,” the Department of Health and Human Services (HHS) said in an FAQ on VAERS.
VAERS data helped doctors adjust the childhood polio vaccine schedule in 1997 in response to about eight to 10 cases of vaccine-induced paralysis they learned had been occurring annually, according to the CDC’s published reports. That change greatly reduced the rare instances of severe side effects after polio vaccinations, wrote journalist Amy Dusto in a May 2022 explainer for the Johns Hopkins Bloomberg School of Public Health, titled “What VAERS Is (And Isn’t): The public database of reported post-vaccination health issues is often misused to sow misinformation.” VAERS also aided in the detection of rare cases of myocarditis following the second dose of COVID-19 mRNA COVID vaccine.
But VAERS is not designed to determine if a vaccine caused an adverse event, as both the HHS FAQ and Hopkins explainer note. It’s critical to remember that a report about a person experiencing a medical condition after vaccination does not establish a link between the two. The COVID vaccine has seen significant misinterpretation of the VAERS data. The database is open to the public and can be searched.
“Since it’s so transparent, people don’t really understand what it’s for,” Kawsar Talaat, M.D., co-director of clinical research for the Hopkins Institute for Vaccine Safety said in the university’s explainer. “They think it’s things that are vetted and have causal relationships with the vaccine.”