Circulating Spike Protein Detected in Post–COVID-19 mRNA Vaccine Myocarditis

• Published in: Circulation (New York, N.Y.) N.Y.), 2023-03, Vol.147 (11), p.867-876
• Main Authors: Yonker, Lael M., Swank, Zoe, Bartsch, Yannic C., Burns, Madeleine D., Kane, Abigail, Boribong, Brittany P., Davis, Jameson P., Loiselle, Maggie, Novak, Tanya, Senussi, Yasmeen, Cheng, Chi-An, Burgess, Eleanor, Edlow, Andrea G., Chou, Janet, Dionne, Audrey, Balaguru, Duraisamy, Lahoud-Rahme, Manuella, Arditi, Moshe, Julg, Boris, Randolph, Adrienne G., Alter, Galit, Fasano, Alessio, Walt, David R.
• Format: Article
• Language: English
• Subjects: Adolescent; Antibodies, Viral; Autoantibodies; Child; COVID-19 - prevention & control; COVID-19 Vaccines - adverse effects; Cytokines; Humans; Myocarditis - etiology; Original s; SARS-CoV-2; Spike Glycoprotein, Coronavirus; Young Adult
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.122.061025

Cases of adolescents and young adults developing myocarditis after vaccination with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-targeted mRNA vaccines have been reported globally, but the underlying immunoprofiles of these individuals have not been described in detail. From January 2021 through February 2022, we prospectively collected blood from 16 patients who were hospitalized at Massachusetts General for Children or Boston Children's Hospital for myocarditis, presenting with chest pain with elevated cardiac troponin T after SARS-CoV-2 vaccination. We performed extensive antibody profiling, including tests for SARS-CoV-2-specific humoral responses and assessment for autoantibodies or antibodies against the human-relevant virome, SARS-CoV-2-specific T-cell analysis, and cytokine and SARS-CoV-2 antigen profiling. Results were compared with those from 45 healthy, asymptomatic, age-matched vaccinated control subjects. Extensive antibody profiling and T-cell responses in the individuals who developed postvaccine myocarditis were essentially indistinguishable from those of vaccinated control subjects, despite a modest increase in cytokine production. A notable finding was that markedly elevated levels of full-length spike protein (33.9±22.4 pg/mL), unbound by antibodies, were detected in the plasma of individuals with postvaccine myocarditis, whereas no free spike was detected in asymptomatic vaccinated control subjects (unpaired test;