Great twitter thread on this subject [0]:

"Data out of Israel ... suggests that vaccine-induced myocarditis is caused by the spike protein. In that case, Covid would cause the same condition in the same person -- but more severely, attached to a fully-fledged living virus.

To be clear: whoever gets heart inflammation from Moderna would’ve almost certainly got it worse from Covid. The issue arises from the spike protein itself. That’s why we don’t see myocarditis from non-MRNA vaccines like Astra Zeneca."

[0]: https://twitter.com/joshzepps/status/1486213462816866304?t=P...