Interestingly, I have read a couple of studies recently that tie COVID-19 to the development of acute mitral valve regurgitation. And it affects both vaccinated and unvaccinated people. At first glance, it would appear the vaccine seems to be irrelevant because of course it does not prevent development of the disease, so both vaccinated and non vaccinated people are at risk of COVID-19. However, since the mRNA vaccine does introduce the COVID spike protein into the body, no one can rule out the possibility that the vaccine also can worsen previously benign mitral valve problems. The more the researchers are discovering, the less we realize we know about the risks of mRNA technology.