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.
As of November 18, 2022 VAERS has stopped putting free text field information in for Europe/UK. This affects the narrative, the country data (previously the highest number of VAERS reports came from the UK), the history, allergies, medications and lab data.
“Disclaimer: At the request of European regulators, CDC and FDA have removed certain data fields (country codes; reported symptom case narrative free text; diagnostic laboratory data free text field; illness at time of vaccination free text field; chronic conditions free text medical history field; allergies free text field) from foreign VAERS reports which were submitted to VAERS and may not comply with European regulations. Domestic (U.S.) VAERS reports are not affected by this process.” [https://vaers.hhs.gov/data/datasets.html]
Some of our totals and charts collected data from these fields. You will notice this change throughout the site where we display all VAERS data. The domestic US data remains unaffected by this change.
The loss of this data does not just affect our site but also researchers across the world who were able to look at patient histories and lab data and have a much more thorough understanding of the reports in question. Scientists like Dr. Jessica Rose (https://jessicar.substack.com/p/the-foreign-data-set-was-gutted-this) have lost significant signals in their data for myocarditis, cancer, miscarriage and more. Dr. Clare Craig was matching VAERS reports to MHRA reports - this will no longer be possible going forward. Aravind Mohanoor - a programmer (https://vaccinedatascience.substack.com/) was working on using the narrative to retrieve AGE data where it was missing in the AGE fields amongst some other fascinating work. And this is just the people we are aware of, there are many more.
Here is one example of what Dr. Rose's signal disappearance looks like.