What VAERS Can and Can’t Do, and How Anti-Vaccination Groups Habitually Misuse Its Data
For decades, an unassuming government vaccine safety surveillance system has done its job, quickly flagging possible side effects and allowing scientists and regulators to investigate further.
But for nearly as long, the Vaccine Adverse Event Reporting System, or VAERS, has also been exploited by people opposed to vaccination. With a publicly searchable database, full of unverified reports of health problems that occurred sometime after vaccination, VAERS has proven irresistible to the anti-vaccination community, which often falsely claims the number of reported deaths or other issues is proof that vaccines are dangerous.
That’s despite the fact that the reports aren’t vetted for accuracy and don’t mean that a vaccine caused a particular problem.
VAERS is an early warning system used to identify potential safety concerns after a vaccine has been authorized or approved in the U.S. It’s often described as a “frontline” system, since it’s frequently the first vaccine safety system to detect a problem. But it’s also noisy and prone to distortion.
“Most of the anti-vaccine stuff that you hear, when they start to talk about how vaccines caused whatever, they’ll point to VAERS data,” Dr. Paul A. Offit, a vaccine expert at Children’s Hospital of Philadelphia, told us. “It is just manna from heaven to get bad information out there.”
While VAERS distortions were already a staple of vaccine misinformation prior to the pandemic, misuse of VAERS exploded with the arrival of the COVID-19 vaccines in late 2020. At FactCheck.org, we’ve written story after story debunking false or misleading claims about the COVID-19 vaccines that were based on misunderstandings about VAERS — and so have our fellow fact-checkers.
And now, one of the most notorious abusers of VAERS data is running for president. Robert F. Kennedy Jr., the nephew of assassinated President John F. Kennedy and a prominent anti-vaccine advocate, announced his campaign challenging President Joe Biden in April. (Kennedy has stated that he is for safer vaccines and is not “anti-vaccine,” but many of his arguments against vaccination are inaccurate or misleading and typical of the movement.)
In 2016, Kennedy founded a group that would become Children’s Health Defense, a nonprofit that traffics in anti-vaccine misinformation and disinformation. Hundreds of stories on Kennedy’s website mention VAERS.
Given the misuse and confusion around VAERS, a research team at the University of Pennsylvania’s Annenberg Public Policy Center — led by APPC Director Kathleen Hall Jamieson and in partnership with Critica Science — has proposed VAERS “Vaccination Safety Monitor” or “Vaccination Safety Watch.” APPC is ’s parent organization.
