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Analysis of Trends in VAERS Data
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February 2012: The Limits of VAERS

This month I want to discuss the limitations of VAERS data. Is it accurate? Is it useful?

Are the conclusions reached in these VAERS blog reports valid?

Let's start off by reviewing the two different ways that vaccine reactions can be monitored: active and passive.

An active monitoring system tracks a patient's entire history, starting before the vaccine is administered, and continuing even after a vaccine reaction. Follow-up interviews may be made after vaccination to increase thoroughness. Such systems are typically managed by a health-care provider and usually include the complete medical record of the patient.

A passive monitoring system (such as VAERS) is one in which reports of vaccine reactions are volunatarily submitted by patients, doctors, and pharmaceutical companies. No reports are filed for healthy people, very little past history is recorded, and few post-reaction follow-ups are available

Passive monitoring systems are less useful than active systems for a number of reasons:

So what good is a passive monitoring system such as VAERS? Most people agree that VAERS is useful as an early-warning indicator of possible vaccine problems. Trends that show-up in VAERS may indicate a problem, which can be further investigated using other data.

Do these blog entries make appropriate use of the VAERS data? Some of the entries do exactly what VAERS is good at: they look through the data and identify possible trends. But other blog entries try to verify a trend by looking at VAERS data, and when this happens, the blog is careful in its wording, saying things like "VAERS data seems to confirm this trend" or "you might want to talk to your doctor about this." Some of the early blog entries (for example December 2009), do discuss issues that can affect the blog's conclusion.

The bottom line is this: We use VAERS because it's all we have. The only active vaccine monitoring system that exists in the U.S. is the Vaccine Safety Datalink, but it is government-private data that is available only to "qualified investigators". Even CDC medical researchers (who do have access to the Vaccine Safety Datalink) often use VAERS data instead. If these blog entries are faulty, then so are those government VAERS analyses that "prove" vaccine safety.

So I will continue to make VAERS blog entries each month and look at all aspects of the data. I hope that I do not mislead, but my goal is to raise awareness of potential vaccine safety issues. I am not a medical researcher (as I state quite clearly). In the end, some will disregard these blog entries because of the problems with VAERS, but hopefully others will find the issues raised here to be useful.

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