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Welcome to the VAERS Wayback Machine
Each month, the U.S. Government publishes a new version of its VAERS database. Most of the differences between versions consist of new VAERS events that were introduced since the previous version. But the government never closes a VAERS event, and may make changes to any event at any time. Sometimes events are even deleted.
The VAERS Wayback Machine has a collection of old versions of the VAERS database, starting in 2003. It allows you to examine the government data more carefully and observe how the data changes over time. Here are some of the things that you can do with the VAERS Wayback Machine:
Enter a VAERS ID number here to see all changes that have been made to that event since it was first published. You can find out when the event first appeared, how it was modified, and if applicable, when it was deleted. See the How Differences are Shown section below for more about interpreting the results.
Select two different VAERS versions to compare them. All VAERS events that are found in both versions will be examined and the differences described. See the How Differences are Shown section below for more about interpreting the results.
Select two different VAERS versions to compare them. All VAERS events that are in just one of the two versions will be listed.
Do a search of an older VAERS database.
Here is a sample event showing differences. Note the use of color coding: Red indicates something that was in the older version and is therefore removed. Green indicates something that is in the newer version and is therefore added.
In the sample event below (a fictitious event), the date of vaccination and onset has changed; the manufacturer of the Flu vaccine has changed, number of days in the hospital was entered (was previously blank), symptoms have changed (four of them have been removed), and the write-up and preexisting conditions were edited.
Differences between 8/31/2010 and 10/5/2010:
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