June, 2014: Injection Sites

VAERS cases have all kinds of information in them. One piece of information is the site of the vaccine: where the injection was given on the patient. Are there any patterns that can be found there?

Before examining the VAERS data, let me point out that a recent paper suggest that the DTP vaccine should be given in the leg, claiming that shots in the leg are less likely to cause minor injection-site reactions.

Now let’s look at the VAERS data. Make a graph of Vaccine Site and Event Category. This will show how the different vaccine sites relate to the different levels of severity (from Not-Serious all the way to Death). Here is what you get:

Only four of the Event Categories have significant numbers, so the others have been removed from the graph. The four Event Categories are “Not Serious” (the most innocuous outcome), “Emergency Room” (still not very serious), “Hospitalized” (potentially serious), and “Death” (very serious).

Only four vaccination sites appear commonly and are mentioned specifically on intake forms. These sites are: LA (left arm), LL (left leg), RA (right arm) and RL (right leg). These four choices are the only ones with significant numbers in the VAERS data.

There are two things to note about this graph:

  • There are more VAERS cases in the arm than the leg. This is obvious by noting that there are more LA cases than LL cases and there are more RA cases than RL cases. Assuming that most people get injections in the arm, the increased numbers makes sense.
  • This trend is reversed for more serious cases. There are more leg cases than arm cases when it comes to hospitalization and death. This distinction is even more noticeable in the most extreme outcome of death. There, we see 2236 LL deaths and only 593 LA deaths. Similarly, there are 2103 RL deaths and only 344 RA deaths.

Does this mean it is more dangerous to get a vaccine in your leg? Are there specific vaccines responsible? Let’s explore the injection sites more closely in the cases where the patient died. Make a graph of Vaccine Site and Vaccines, then set Died to “yes” in Section 4 of the search form. This will show which vaccines contributed to the problem of leg-site injections and death.

From the looks of it, it seems that deaths after vaccinations in the leg occur across a wide variety of vaccines. The only vaccine with a strong preference for death after an arm injection is Influenza. Perhaps flu shots, which are typically given to older people, don’t use the leg much.

So the above mentioned paper is correct: to avoid minor vaccine reactions (such as injection-site soreness) a shot in the leg is probably the better choice. But many more serious reactions happen when the shot is in the leg. VAERS data suggests that a shot in the arm might be better at keeping you alive.

As always, you should discuss these issues with your physician before making any decision.