Risk Analysis of Moderna and Pfizer Vaccines: Update

Since I first published my vaccine risk analysis, one person (the first) has died shortly after receiving the vaccine and possibly because of the vaccine: click here for an article on Dr. Gregory Michael.

I think it's worthwhile to take a look at this and see if this affects the bottom-line risk analysis.

Did Dr. Michael die because of the vaccine?

Bottom line: not certain, but quite possibly.

In more detail:

Dr. Michael developed a condition 3 days after having been vaccinated called "acute immune thrombocytopenia" (ITP), which happens when your immune system begins attacking your own blood platelets.  In about 5% of adult cases, this can lead to death by hemorrhaging, which is what happened to Dr. Michael.

Since vaccines work by triggering the body's immune system, I had already identified immune system overreactions as the most likely cause of adverse side effects from the new vaccine.  It is therefore quite plausible that the vaccine was the cause of, or at least the trigger for, the condition that lead to Dr. Michael's death.

However, we also cannot rule out tragic coincidence at this time.  As of today's date (January 14th), about 11 million doses of the new vaccines have been administered in the U.S. alone.  ITP is rare, but it occurs in about 2 adults per 100,000 each year.  This means that if you picked 11 million adults at random in the U.S. and did nothing to them for one month, you would expect about 18 of them to develop ITP just by chance, and given a 5% fatality rate, one of those 18 or so would be likely to die.  One death from ITP out of 11 million doses in one month therefore is not above the level where it could be an unfortunate coincidence.

However, I feel that it is somewhat more likely than not that the vaccine triggered the condition in Dr. Michael in this case.  ITP is normally triggered by something that activates the immune system: either a pathogen or a medicine such as a vaccine which triggers the immune system.  In Dr. Michael's case, the only such cause we know of is the vaccine; he wasn't otherwise sick, nor had he taken another medicine that could have triggered the condition (that I could tell by the report, anyway).  So I think it is reasonable to suspect that the vaccine had a part in causing his death, even if we can't rule out coincidence and an unknown other cause.

Was Dr. Michael susceptible to ITP even aside from the vaccine?

Probably, yes.  In my risk analysis, I emphasized that many of the mechanisms by which the vaccine might cause serious side effects in its recipient are also possible as side effects of the virus itself.  It stands to reason that if the side effect (ITP in this case) is caused by an immune reaction to the vaccine and if the whole point is for the vaccine to trigger the same immune reaction that the virus would, then that side effect of the vaccine would also be a side effect of the virus.

This does turn out to be the case with ITP.  Although not listed in my short-list of known serious side effects of Covid-19, it turns out that ITP has already been identified as one of the myriad possible symptoms and syndromes that can be triggered or caused by Covid: see this article here.  We don't know the specific reasons why some people can be susceptible to ITP and other people aren't, but genetics are vaguely suspected.  It is therefore more likely than not that Dr. Michael was in some danger of developing ITP from catching Covid, as well as from taking the vaccine.  This is, however, impossible to know for sure at this point.

Should I update the risk analysis bottom line because of this occurrence?

No, that isn't necessary.  Previously, I had set the risk of death from getting both doses of the vaccine at a maximum of 1 in 1 million, which was based on 2 million doses administered at the time with no deaths.  We now have 11 million doses administered and 1 known death.  If we attribute this death completely to the vaccine, that means I should adjust the chances of dying from the vaccine down to 1 in 6.5 million.

However, as I purposefully decided to under-rate the risks of the vaccine and over-rate the risks of the virus and data is still relatively sparse, I will keep the risk at 1 in 1 million for now.