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Analysis of Trends in VAERS Data
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December, 2011: Yearly wrapup

Another year of VAERS data has been published by the government, so it's time for a yearly wrap-up. As I have done in past years, I will look at the number of VAERS events that have been posted since the start of the program in 1990. The search is simple: a Graph of Year of Appearance (the year in which a particular VAERS event appeared in the data):

The graph shows a surprising result for 2011: it is the first year that had a noticeable decrease in the number of VAERS events. The slight decrease between 2009 and 2010 is nothing compared with the nearly 20% drop between 2010 and 2011 (from 36,806 events in 2010 to 29,908 events in 2011).

What changed? Let's look at individual vaccines. Make a Graph of Year of Appearance and Vaccine Type (the Vaccine Type is the disease that the vaccine prevents).

Although there were fewer reports for nearly all of the vaccine types, one of them (Flu) went down significantly. In fact, the change in the number of Flu-related events (down from 16,742 in 2010 to 9,758 in 2011) more than accounts for the overall drop in VAERS events.

Of course, when looking at yearly Flu seasons it is important to note that they occur in the winter months, which span two different calendar years. So it is more useful to graph Month of Appearance instead of Year of Appearance. Doing that for the past few years confirms the decrease in Flu-related VAERS events during this current Flu season:

The trend is unmistakeable: Flu-related VAERS events are way down. In my September Blog Entry, I predicted a bad year for Flu-related VAERS events, but apparently I was wrong.

Of course, the number of Flu-related VAERS events rose significantly in the previous two years, no-doubt fueled by the H1N1 scare, so this may simply be the "normalizing" of an unusual spike. But Flu shots are still pushed hard during the winter months and many people still get the vaccination.

Is the decrease in the number of Flu-related VAERS reports caused by a safer Flu vaccine? Has the unusually late Flu season resulted in people avoiding the shot until 2012, leaving 2011 numbers low? Or are people intentionally avoiding getting the Flu vaccine?

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