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Analysis of Trends in VAERS Data
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April 2010: Getting multiple vaccines at one time

We live in a fast-paced society and we like to get things done quickly. We don't want to visit the doctor multiple times to get all of our innoculations, so we get all of them at once.

Is this wise?

This month I will attempt to answer that question using data from VAERS. Unfortunately, it is difficult to answer this question by using VAERS data because it shows only the negative outcomes that occur after a vaccination. There is no way of knowing how many vaccinations were given that had no adverse effects. Therefore lets ask a different question:

Does the rate of "serious" VAERS reports increase as more vaccinations are given at the same time?

What is a "serious" VAERS report? Each report has a number of possible outcomes which include:

CDC Wonder defines "serious" as any combination of Death, Permanent disability, Life threatening, or Hospitalized (see So we can answer this month's question by asking two different questions: (1) what proportion of the VAERS reports are serious and (2) how many different vaccines were given to those people?

First we will ask for a breakdown of VAERS reports by the number of vaccines given. To do this, go to MedAlerts and under "Show Table" set the Tabulate field to "Vaccine Count". The results are here:

Number of Vaccines Given at Once Number of VAERS Reports
1 206,300
2 50,963
3 44,186
4 23,825
5 4,721
6 760
7 82
8 28
9 4
11 2
Most of the VAERS reports involve just one vaccination, but there are a significant number of reports in which more than one vaccine was given. Some VAERS reports describe a surprisingly large numbers of vaccinations that were given at once (as many as 11!) However, there are relatively few of these extreme reports, so to simplify the analysis, we will consider only reports where 5 or fewer separate vaccinations were given at once.

Next we want to break this down according to the outcome of each VAERS report. To do this, go to MedAlerts and under "Show Table" set the Tabulate field to "Outcome Category" and under that set the next field to "Vaccine Count". The result is a two-level table showing the different outcomes broken down by the number of vaccines that were given at once. Here is the first part of the table, showing the number of VAERS reports that listed a death, and the number of vaccines that were given:

Number of Vaccines Given at Once Number of Deaths
1 2028
2 651
3 951
4 612
5 121
At first, it would seem that the worst thing to do is to get just one vaccine, because the most number of deaths were reported among people who did that. But recall that most of the VAERS reports involved just one vaccination, so in order to make sense of the numbers, it is necessary to "normalize" them, dividing the number of deaths by the total number of VAERS reports. Doing this gives different numbers:
Number of Vaccines Given at Once Number of Deaths Number of VAERS Reports Deaths per Report
1 2028 206,300 0.00991
2 651 50,963 0.01287
3 951 44,186 0.02167
4 612 23,825 0.02593
5 121 4,721 0.02588
Now the numbers make sense. And not only that, they show a clear trend: when one vaccine is given, a smaller proportion of the VAERS reports show a death, and as more vaccines are given, higher proportions of the VAERS reports show a death.

Putting all of these numbers into a spreadsheet gives the following graph. (Note that the numbers associated with each outcome are so very different, that it is necessary to do a second pass of normalizing to make the bars in each category have similar lengths. Without this, some categories would have all of their bars be very short and others would have very long bars.)

What does this graph show? Let's discuss each category separately: In conclusion, VAERS data seems to show that getting multiple vaccines in a single office visit may not be as safe. Concerned patients should discuss this with their doctor.

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