VAERS CDC Disclaimer

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:

Vaccine providers are encouraged to report any clinically significant health problem following vaccination to VAERS, whether or not they believe the vaccine was the cause.

Reports may include incomplete, inaccurate, coincidental and unverified information.

The number of reports alone cannot be interpreted or used to reach conclusions about the existence, severity, frequency, or rates of problems associated with vaccines.

VAERS data is limited to vaccine adverse event reports received between 1990 and the most recent date for which data are available.

VAERS data do not represent all known safety information for a vaccine and should be interpreted in the context of other scientific information.

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.

What are the Foreign Reports and why do we include them?

Published on

06 August 2022

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Wonder has very little to say on the issue of what a nondomestic report is. From their Advisory Guide:

“VAERS occasionally receives case reports from US manufacturers that were reported to their foreign subsidiaries. Under FDA regulations, if a manufacturer is notified of a foreign case report that describes an event that is both serious and unexpected (in other words, it does not appear in the product labeling), they are required to submit it to VAERS. It is important to realize that these case reports are of variable data quality and completeness, due to the many differences in country reporting practices and surveillance system quality.“

The strange thing about this is VAERS implies here that the Foreign Reports are occasional and insignificant. The numbers say otherwise. The Foreign Reports make up close to half of the reports in VAERS and more than half the deaths. For further breakdowns on Foreign Reports you can also look here: https://vaersanalysis.info/2021/07/10/4-weeks-where-foreign-vaers-deaths-reports-vastly-outnumbered-us-reports/

We use the foreign records by default because the VAERS data is the data and we are 'OPENVAERS' not 'OPEN USONLY VAERS'. This is true of the Wonder site as well. You can access all the data not just the US data. One thing to keep in mind is the "US Reports" in the Wonder system include territories and unknowns. It is not a true breakdown of JUST US state data. Additionally, as seen below, the Foreign data contains mistakes of US data marked as "FR".

Here is a breakdown of the distribution of Foreign Reports as of July 29, 2022. Like the Lot Numbers these figures must be taken with a grain of salt due to the really error prone and messy nature of the data in this field*. These numbers are drawn from the data without any cleaning (this is how we do all the numbers). These are the countries with >500 reports per country code.

* These reports are marked as Foreign (come in the Foreign data files) and are marked with type "WA" which normally would be Washington State. No way to know what these are, they are not COVID reports, they are dated from 1990-2016. There are also 200+ reports from the US that are in the Foreign set (not visible on this graph).

VAERS CDC Disclaimer

What are the Foreign Reports and why do we include them?

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