[burpee]

I've had the exact some happen (It's rare, but here I am), including a transient ischemic stroke while having virtually no platelets.

There is no real understanding for the cause of immune thrombocytopenia in the first place, but the combination of low platelets and clotting happens in quite a few cases.

Platelets take on a lot of roles beyond clotting (for example they transport serotonin, which itself has been linked to clotting) and clotting itself is about more than just platelet counts (which would need a few pages to even start to explain).

Once the immune system targets platelets though, unexpected things tend to happen beyond just uncontrolled bleeding, none of which are particularly well understood due to the low number of cases. The cause of idiopathic thrombocytopenia is most commonly attributed to an immune response, although it can have several other causes.

What I can say is that thrombocytopenia following a viral infection is more common than it appears to be following this vaccine. I believe this would be a more fair comparison than to compare it against the general population.

The percentage of people who would have this same stroke when having COVID-19 would in all probability be much much higher.

[airhead969]

Perhaps the few available platelets were all consumed in the act of forming the clot so they registered as low because they were gone?

[burpee]

That would cause systemic problems for the person and almost certain death.

Platelets are filtered out of the blood by the spleen and then stored or cleaned up there. The spleen likely just cleans them up as per instructions from the immune system. On the other side are production problems where your bone marrow stops producing platelets, but that is more commonly due to cancers or cancer treatments.