A new study sheds light on what may be causing very rare cases of heart inflammation in young men after receiving an mRNA Covid vaccine.
Early hypotheses as to what was driving the heart inflammation, called myocarditis, included an allergic response to the vaccine, vaccine-induced antibodies, or an autoimmune response in which the immune system attacks the body’s own healthy tissue by mistake. But the study, published Friday in Science Immunology, doesn’t find evidence for any of these mechanisms.
Instead, when looking at cases in 23 patients, the researchers found signs of a revved-up immune system driven by inflammatory proteins.
“We were a little relieved that what we found was the inflammation-induced myocarditis,” said Akiko Iwasaki, one of the authors and a professor of immunobiology at Yale University. In particular, if the cases were driven by an autoimmune response, they “would be a little bit more difficult to treat and deal with.”
