And a lot of you write about palpitations, which can also be caused by stress and anxiety. I'm 30, in good physical shape, and used to have weekly episodes with irregular heartbeats due to severe stress. Now I'm vaccinated (which is for 99.999% of us obviously completely irrelevant to experiencing this, but a lot of commenters draw that conclusion) and the palpitations are gone. Let's not base conclusion on anecdotal evidence, please. For the same reason that my grandpa lived until 85 while smoking since he was 13.