The best I can tell,

SARS attacks multiple cells all over your body, particularly endothelial cells, which make up your vascular system.. and then your immune system goes hog wild messing you up further trying to clean it out.

Then the clots from it wreak havoc all over your body which is particularly problematic in the brain, heart, lungs, kidneys, and liver (all things SARS infections seem to damage).

To top it off the virus isn’t always purged and can be found in those organs post-acute phase

This is how I’ve simplified it in my head anyway

SARS is, and always was, a vascular disease. We knew this 20 years ago after the 2003 SARS outbreak.

– Anthony