I am curious how your sister's pericarditis was diagnosed. I had my Pfizer booster two days ago and got costochondritis, which feels just like pericarditis. Is it possible your sister had costochondritis instead (inflammation of connective tissue between ribs and breast bone).

Now that there is are antiviral pills about to come on the market, I supposed they could offer another path of safety. I have paroxysmal afib but my 3 Pfizer doses did not trigger any arrhythmias.