Editors Choice

New Research Clarifies Cause of Myocarditis After mRNA Vaccine

Vaccination against SARS CoV-2 has made a tremendous difference and impact on the course of the SARS CoV-2 pandemic. This is indisputable. Vaccination against SARS CoV-2 has saved lives. That is indisputable.

That said, it is clear that vaccination against SARS CoV-2 also comes with risks. It is not completely benign. That is also indisputable. Specifically, vaccination against SARS CoV-2 has been associated with myocarditis/pericarditis, especially in adolescent and young adult males.

The mechanism of this very rare, albeit very real, complication (estimated to be between 0 to 35.9 cases per 100,000 across age groups and mRNA vaccine cohorts) has been thought to be either an allergic reaction, an autoimmune reaction from the vaccine, or a cross-reaction from the antibodies generated by the vaccine itself.

Researchers from Yale University have elucidated the actual cause of myocarditis. They studied 23 patients with vaccine-associated myocarditis and/or pericarditis. They did extensive and exquisite studies on these patients, and here their conclusions:

our results demonstrate up-regulation in inflammatory cytokines and corresponding lymphocytes with tissue-damaging capabilities, suggesting a cytokine-dependent pathology, which may further be accompanied by myeloid cell–associated cardiac fibrosis. These findings likely rule out some previously proposed mechanisms of mRNA vaccine–-associated myopericarditis and point to new ones with relevance to vaccine development and clinical care.

Thus, it is the actual immune system itself – revved up by the vaccine – that directly damage the heart muscle itself. Now, this raises a number of questions: why more often in young males? Why the heart and not other organs? If there could be scarring in the heart, then what are the long-term effects? What does this mean for future mRNA vaccines? Hopefully, these and even more questions will be answered with further research.

Yes, the cohort is quite small, and it may be difficult to extrapolate these findings to all patients with vaccine-induced myocarditis. Nonetheless, the findings are an important contributor to the literature. It emphasizes the great importance to follow these patients long-term to make sure they don’t have any long-term complications. In addition, it is quite important to highlight what the researchers themselves pointed out about their findings:

It is also critical to contextualize the rare risk of adverse events and potential clinical sequelae after SARS-CoV-2 vaccination in comparison with the greater risks of sequelae (including myocarditis), hospitalization, and/or death resulting from infection with SARS-CoV-2.

Indeed, according to the CDC, the risk of cardiac complications of the infection itself far far outweighs the risk of myocarditis from the vaccine:

Source: https://www.cdc.gov/mmwr/volumes/71/wr/mm7114e1.htm#T2_down

Hopefully, further research will add to this study’s important body of knowledge and help us develop even safer vaccines for the next pandemic.

Study Reference: Anis Barmada, et al. Cytokinopathy with aberrant cytotoxic lymphocytes and profibrotic myeloid response in SARS-CoV-2 mRNA vaccine–associated myocarditis. Sci.Immunol.8,eadh3455(2023). DOI:10.1126/sciimmunol.adh3455

Dr. Hesham A. Hassaballa

Dr. Hesham A. Hassaballa is a NY Times featured Pulmonary and Critical Care Medicine specialist in clinical practice for over 20 years. He is Board Certified in Internal Medicine, Pulmonary Medicine, Critical Care Medicine, and Sleep Medicine. He is a prolific writer, with dozens of peer-reviewed scientific articles and medical blog posts. He is a Physician Leader and published author. His latest book is "Code Blue," a medical thriller.

Recent Posts

Purpose at the Center: Craig Martin’s “Rare” Commitment to Biopharma and Patients

Craig Martin is a strategic chameleon in health innovation. He is equally at home in…

2 days ago

The Silent Additive: What Singapore Street Food Taught Me About Ultra-Processed America

I Ate More. I Weighed Less. In Malaysia, I ate like a poet unchained. Noodles…

2 days ago

The Algorithm That Gave Me Pause Tonight and “Hooked” Me

I had never envisioned a computer responding to me and “telling” me that it had…

2 days ago

Why Israel’s Brilliant Climate Solutions Are Still Invisible

If you work in climate or environmental innovation, you’ve probably felt the shift: it’s getting…

1 week ago

The Surprising Health Benefits of Walking on Uneven Ground — And Why You Should Start Today

Most people walk to relax. I came to Borneo to let the ground fight back.…

1 week ago

Human First: Reclaiming Empathy in Our Love Affair with Health Tech

[Reprinted with permission by By Light-it, in collaboration with Digital Health Insider] We are a…

1 week ago

This website uses cookies. Your continued use of the site is subject to the acceptance of these cookies. Please refer to our Privacy Policy for more information.

Read More