“...a group of beachgoers encountered difficulties while returning to the shore after swimming near a sandbar in the Gulf of Mexico.”
Rip tide? Struggling against that might trigger a heart condition that may or may not have anything to do with the Vax. Or he could have been pulled under and just drowned.
All speculation aside, I had a near-deatg experience with a rip tide over in Jacksonville a number of years back, that ain’t no joke.
Rip currents can be deadly because even fit but casual beach goers tend to be unaware of the risks and become quickly exhausted and then drown. The description of other swimmers as also being in trouble fits the pattern of a rip current.