...However, histopathological analyses of the brain uncovered previously unsuspected findings, including acute vasculitis (predominantly lymphocytic) as well as multifocal necrotizing encephalitis of unknown etiology with pronounced inflammation including glial and lymphocytic reaction. In the heart, signs of chronic cardiomyopathy as well as mild acute lympho-histiocytic myocarditis and vasculitis were present.
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Sounds like the mRNA was injected into a vein, it circulated throughout his body, then the spike protein replication process occurred in his brain and heart. The body mounted an immune response and did what the immune response does, it killed all the infected cells. Unfortunately these were in tissue he needed to live.
For my booster #2, I had the nurse aspirate the syringe to make sure the needle was in muscle.
That was my last booster, too.
Aspiration before the covid injection was specifically not recommended.