[LadyDoc]

Auto immune thrombocytopenia can be caused by drugs, viruses, rheumatoid disorders etc. So they will check if the vaccine could have caused it.

However, developing 3 days after the vaccine is too fast for an autoimmune reaction. A toxic reaction can happen that fast, but the immune system takes 7 to 14 days to develop antibodies.

[ProtectOurFreedom]

Interesting point about the timing. Could he have had a chronic pre-existing case turned acute?