Myocarditis may not be linked to COVID-19 vaccine: Yale study

In the middle of a whirlwind discussion on COVID-19 vaccines and the risk of myocarditis or pericarditis, Yale researchers find heart disease could be linked to a person’s immune system rather than a COVID-19 vaccine.

The study analyzed 23 patients aged 13 to 21 who developed vaccine-associated myocarditis and/or pericarditis, which are swelling of the heart and inflammation of the tissues around the heart, respectively. Science published the study on May 5.

Twenty-one researchers from Yale University School of Medicine in New Haven, Connecticut, and two from the New York-based Icahn School of Medicine at Mount Sinai, conducted the study. In it, they found that T cells that entered heart tissue exhibited “antigen-independent and cytokine-dependent activation after vaccination.”

The authors said they observed that “susceptible individuals may experience an enhanced cytokine-induced immune response to vaccination and, in particular, soon after the second dose, consequently activating immune effectors and causing cardiac inflammation.” They added that their findings “probably eliminate” concerns about whether vaccines induced the rare cardiac events.

They concluded that more research is needed to understand whether this is due to virtual memory responses, epigenetic reprogramming of effector subsets, or innate immune memory.