Combined Adaptive Immune Mechanisms Mediate Cardiac Injury After COVID-19 Vaccination

S Silvia Fanti (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, United Kingdom (S.F., F.M.-B.).) C Carlene Dyer (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) I Inga Jóna Ingimarsdóttir (Departments of Cardiology (I.J.I.), Landspitali – The National University Hospital of Iceland, Reykjavik, Iceland.) D Daniel Harding (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) G Guosu Wang (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) A Antonio D’Amati (Department of Translational Biomedicine and Neuroscience, University of Bari Medical School, Bari, Italy (A.D.).) E Eriomina Shahaj (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) A Adalbjorg Ýr Sigurbergsdóttir (Department of Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland (I.J.I., A.Ý.S., H.T., O.B.G., S.F.B., B.R.L.).) H Helga Thórsdóttir (Department of Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland (I.J.I., A.Ý.S., H.T., O.B.G., S.F.B., B.R.L.).) O Oddný Brattberg Gunnarsdóttir (Department of Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland (I.J.I., A.Ý.S., H.T., O.B.G., S.F.B., B.R.L.).) S Stavroula Kanoni (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) P Paul Wright (Barts Heart Centre, Barts Health NHS Trust, St Bartholomew’s Hospital, West Smithfield, London, UK (D.H., P.W., S.A.M.).) J John Martin J Jamie Chorlton (The Salt Hill Charity, London, UK (J.M., J.C., Z.H.).) Z Zoe Hollowood (The Salt Hill Charity, London, UK (J.M., J.C., Z.H.).) S Siggeir Fannar Brynjólfsson (Immunology (S.F.B., B.R.L.), Landspitali – The National University Hospital of Iceland, Reykjavik, Iceland.) B Bjorn Rúnar Lúdvíksson (Immunology (S.F.B., B.R.L.), Landspitali – The National University Hospital of Iceland, Reykjavik, Iceland.) E Egle Solito (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) S Serena Bert (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) J Jack M. Keane (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) S Saidi A. Mohiddin (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) M M. Paula Longhi (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).) F Federica M. Marelli-Berg (William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).)

Abstract

BACKGROUND: The COVID-19 pandemic, caused by SARS-CoV-2, has led to the first approval of mRNA vaccines in humans. By producing the full-length SARS-CoV-2 Spike protein, they induce protective antiviral immunity. Acute myopericarditis (AMP) development after vaccination has repeatedly been reported; however, the pathogenesis of this complication remains elusive. METHODS: In-depth phenotyping of peripheral blood T cells was undertaken in cohorts of patients who developed AMP after mRNA vaccination, patients hospitalized for severe COVID-19, and healthy subjects with no cardiac side effects after mRNA vaccine. Validation studies were carried out using an experimental model of cardiac inflammation, in which a shared epitope elicits functional responses in patients and mice and induces AMP. RESULTS: We show that T cells from patients with AMP recognize vaccine-encoded Spike epitopes homologous to those of cardiac self-proteins. One of these epitopes, mimicking an amino acid sequence from a cardiomyocyte-expressed K + channel, induced AMP in mice. When functional responses to the Kv2 were analyzed, patients with AMP after mRNA vaccination, but not patients with COVID-19, displayed an expanded pattern of cytokine production similar to that observed in AMP mice and in autoimmune myocarditis. Crucially, T-cell autoimmunity segregates to cardiotropic cMet (c-mesenchymal epithelial transition factor)–expressing T cells and is prevented by cMet inhibition, suggesting that heart homing imprinting, permitted by the unique mRNA vaccine biodistribution, is required for AMP development. CONCLUSIONS: AMP development after mRNA vaccines is mediated by distinct immune components, including molecular mimicry, T-cell receptor affinity, and, importantly, homing imprinting.

Article Details

Journal Circulation
Volume / Issue Vol. 152, Issue 21
Published November 25, 2025
Pages 1485-1500
ISSN 0009-7322
Publisher Lippincott Williams & Wilkins

Journal Info

Circulation

Lippincott Williams & Wilkins

ISSN: 0009-7322 Health Sciences

Authors (23)

S

Silvia Fanti

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, United Kingdom (S.F., F.M.-B.).

C

Carlene Dyer

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

I

Inga Jóna Ingimarsdóttir

Departments of Cardiology (I.J.I.), Landspitali – The National University Hospital of Iceland, Reykjavik, Iceland.

D

Daniel Harding

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

G

Guosu Wang

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

A

Antonio D’Amati

Department of Translational Biomedicine and Neuroscience, University of Bari Medical School, Bari, Italy (A.D.).

E

Eriomina Shahaj

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

A

Adalbjorg Ýr Sigurbergsdóttir

Department of Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland (I.J.I., A.Ý.S., H.T., O.B.G., S.F.B., B.R.L.).

H

Helga Thórsdóttir

Department of Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland (I.J.I., A.Ý.S., H.T., O.B.G., S.F.B., B.R.L.).

O

Oddný Brattberg Gunnarsdóttir

Department of Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland (I.J.I., A.Ý.S., H.T., O.B.G., S.F.B., B.R.L.).

S

Stavroula Kanoni

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

P

Paul Wright

Barts Heart Centre, Barts Health NHS Trust, St Bartholomew’s Hospital, West Smithfield, London, UK (D.H., P.W., S.A.M.).

J

John Martin

J

Jamie Chorlton

The Salt Hill Charity, London, UK (J.M., J.C., Z.H.).

Z

Zoe Hollowood

The Salt Hill Charity, London, UK (J.M., J.C., Z.H.).

S

Siggeir Fannar Brynjólfsson

Immunology (S.F.B., B.R.L.), Landspitali – The National University Hospital of Iceland, Reykjavik, Iceland.

B

Bjorn Rúnar Lúdvíksson

Immunology (S.F.B., B.R.L.), Landspitali – The National University Hospital of Iceland, Reykjavik, Iceland.

E

Egle Solito

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

S

Serena Bert

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

J

Jack M. Keane

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

S

Saidi A. Mohiddin

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

M

M. Paula Longhi

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).

F

Federica M. Marelli-Berg

William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, UK (S.F., C.D., D.H., G.W., E.S., S.K., E.S., S.B., J.M.K., S.A.M., M.P.L., F.M.M.-B.).