Welcome to the VAERS Wayback Machine

Each month, the U.S. Government publishes a new release of its VAERS database (they did weekly releases from 12/8/2009 to 6/9/2010 and from 12/10/2020 to 9/29/2023). Most of the differences between releases consist of new VAERS cases that were introduced since the previous release. But the government never closes a VAERS case, and may make changes to any case at any time. Sometimes cases are even deleted.

The VAERS Wayback Machine has a collection of old releases 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:

Follow Changes to a VAERS Case

Enter a VAERS ID number here to see all changes that have been made to that case since it was first released. You can find out when the case 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.

Find Differences between Cases in Two Releases of the VAERS Database

Select two different VAERS releases. All cases that changed from one release to the other are displayed, and the differences described. See the How Differences are Shown section below for more about interpreting the results.

Release 1:
Release 2:

Find Added/Removed Cases Between Two Releases of the VAERS Database

Select two different VAERS releases. All cases that were added or deleted between the releases will be shown.

Release 1:
Release 2:

Search an Older Release of the VAERS Database

Do a search of an older VAERS release.

Release:

How Differences are Shown

Here is a sample case showing differences. Note the use of color coding: Red indicates something that was in the older release and is therefore removed. Green indicates something that is in the newer release and is therefore added. In the sample below (a fictitious case), many things have changed.

Color Schemes (Before/After):

Differences between 8/31/2010 and 10/5/2010:

Changed: Vaccination Date, Onset Date, Vaccine Manufacturer, Symptoms, Hospitalized, Preexisting Conditions, Write-up

VAERS ID:	274544/274544
Age:	1.0
Sex:	Male
Location:	Louisiana

Vaccinated:	2005-11-29/2006-11-30
Onset:	2005-11-29/2006-11-30
Submitted:	2006-12-04
Entered:	2006-12-04

Vaccination / Manufacturer (2 vaccines)	Lot / Dose	Site / Route
FLU: INFLUENZA (SEASONAL) (FLUZONE) / AVENTIS PASTEUR/SANOFI PASTEUR	U2174KA / 0	IM / LL
HEPA: HEP A (HAVRIX) / MERCK & CO. INC.	0560R / 0	IM / RL

Administered by: Public Purchased by: Public
Symptoms: Anaphylactic reaction, Angioneurotic oedema, Dyspnoea, Eye swelling, Swelling face, Vaccination complication, Wheezing

Life Threatening?
Died?
Permanent Disability?
Recovered? Yes
ER or Doctor Visit?
Hospitalized? Yes, days: (blank)/1
Previous Vaccinations:
Other Medications: J-tan 2ml twice a day
Current Illness:
Preexisting Conditions: SGA, Hemangioma, Chiritis/Rhinitis, Term baby
Diagnostic Lab Data:
CDC 'Split Type':

Write-up:Administration to a child <4 yold. Initial case report received from a pediatrician via agency on 04 NOV 2009. A 1-year-old male patient was accidentally vaccinated with FLUVIRIN 2009/2010 i.m. on 30 OCT 2009. No adverse effect was reported. Company assessment: Seriousness criterion: not serious. Causality: not applicable. No measures necessary.