>>13849331See for yourself :-
https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciab707/6353927tl;dr if the jab somehow pierced a blood vessel and the vax got into your blood circulation and reached your heart, you are gonna die, because the mrna and viral vector mechanism makes your cells attack other ones of your own cells, not all cells in our body, organs etc can be re produced.
You can see the state of heart in the pictures of mice on which the experiments were conducted.
But the thing the anti vax crowd misses here is that, cases in which intramuscular vaccines pierce a blood vessel are low, like 1 in 1000 or something. You can always choose to aspirate if you are concerned.
However the thing is that, in muscular young males the likeliness of the above happening increases. The probability of the hab hitting a blood vessels increases a lot, this is the reason roiders often aspirate while taking the roids (if it gets into the blood you die)
