Covid is a MUCH bigger risk than the vaccine. Most cases of vaccine-associated myocarditis are mild and resolve quickly. (And not all get hospitalized, which may be the difference between your Israeli myocarditis cases and your US Covid hospitalizations). I haven’t seen data on this with the vaccine, but selenium deficiency is a known risk factor for viral myocarditis with other viruses, so you could put him on selenium 200 mcg a day as a preventive (or have him eat a handful of Brazil nuts a week, they are a rich source).
To put this into perspective though, allergic reactions to penicillin cause 500 deaths a year in the U.S. lightning kills 49 per year. So they are still more likely to be killed by lightning than by the vaccine.
