shipsAreWeird123 t1_j7bru2b wrote on February 5, 2023 at 4:58 PM

Reply to comment by JerrodDRagon in New evidence suggests that ‘hybrid’ immunity, the result of both vaccination and a bout of COVID-19, can provide partial protection against reinfection for at least eight months. Immunity acquired by booster vaccination alone seems to fade somewhat faster. by MistWeaver80

If people were getting vaccinated as soon as they could, in the US, for many people the circulating variants were different by the time you needed to get your fourth booster. It became more clear that we needed a bivalent booster, but it wasn't quite out yet.

My guess is that it wasn't that it wasn't effective, just less effective than an updated one would be.

Eating well and exercising protects your heart. COVID causes a lot of clotting. It might just be that people with healthy hearts are better able to handle the stress on the body than people whose hearts are already stressed.