VAERS accepts reports of adverse events and reactions that occur following vaccination. Healthcare providers, vaccine manufacturers, and the public can submit reports to the system. While very important in monitoring vaccine safety, VAERS reports alone cannot be used to determine if a vaccine caused or contributed to an adverse event or illness. The reports may contain information that is incomplete, inaccurate, coincidental, or unverifiable. In large part, reports to VAERS are voluntary, which means they are subject to biases. This creates specific limitations on how the data can be used scientifically. Data from VAERS reports should always be interpreted with these limitations in mind.
The strengths of VAERS are that it is national in scope and can quickly provide an early warning of a safety problem with a vaccine. As part of CDC and FDA’s multi-system approach to post-licensure vaccine safety monitoring, VAERS is designed to rapidly detect unusual or unexpected patterns of adverse events, also known as “safety signals.” If a safety signal is found in VAERS, further studies can be done in safety systems such as the CDC’s Vaccine Safety Datalink (VSD) or the Clinical Immunization Safety Assessment (CISA) project. These systems do not have the same scientific limitations as VAERS, and can better assess health risks and possible connections between adverse events and a vaccine.
Key considerations and limitations of VAERS data:
VAERS data available to the public include only the initial report data to VAERS. Updated data which contains data from medical records and corrections reported during follow up are used by the government for analysis. However, for numerous reasons including data consistency, these amended data are not available to the public.
In 2016 Dr. Cody Meissner authored an article for AAP News in which he stated "In 2012, reports were received from health care providers (41%), manufacturers (29%), other sources (17%) and vaccinees or families (14%)." 1
Then according to the ODPHP (Office of Disease Prevention and Health Promotion) report about VAERS from Healthy People 2020:
“The majority of VAERS reports are sent in by vaccine manufacturers (37%) and health care providers (36%). The remaining reports are obtained from state immunization programs (10%), vaccine recipients (or their parent/guardians, 7%) and other sources (10%).”
So at the time of this writing, 83% of reporters were from HCWs, Pharma and Governmentally based sources.2
Finally, we have from early April 2021 Scott McLachlan and colleagues downloaded the 2021 US VAERS Dataset. They identified health service employees as the reporter in at least 67% of the reports, while pharmaceutical employees were identified as the reporter in a further 5%. Lay people were identifiable as the reporter in only 28% of the reports. A total of 72% HCWs and pharma.3