Intravenous injection of COVID-19 mRNA vaccine may induce acute myocardial pericarditis in a mouse model.
PMID: 34406358 PMCID: PMC8436386 DOI: 10.1093 / cid / ciab707
Commentary
This study was designed to investigate the cardiac effects of accidental intravenous injection of vaccine, as myocardial pericarditis has been reported after immunization with COVID-19 mRNA vaccine.
Clinical signs, histopathological changes, tissue mRNA expression, and serum levels of cytokines/chemokines in Balb/c mice at various time points after intravenous (IV) and intramuscular (IM) vaccine injection were compared with normal saline (NS) controls.
Results showed significant weight loss and higher serum cytokine/chemokine levels in the IM group 1-2 days post-injection (dpi), confirming that only the IV group developed histopathological changes of pericarditis, as evidenced by necrosis with cardiomyocyte degeneration, apoptosis, and adjacent inflammatory cell infiltration.
They found no evidence of coronary artery or other cardiac pathology, but calcified deposits in the visceral pericardium.
Expression of the SARS-CoV-2 spike antigen by immunostaining was occasionally seen in infiltrating immune cells, cardiomyocytes and endocardial vascular endothelial cells in the heart or injection site, but not in skeletal muscle cells.
Histological changes in myocardial pericarditis after the first IV priming dose persisted for 2 weeks and were markedly exacerbated by the second IM or IV booster dose, and cardiac tissue mRNA expression of IL-1β, IFN-β, IL-6 and TNF-α increased significantly from 1 dpi to 2 dpi in the IV group, but not in the IM group, compatible with the presence of myocardial pericarditis in the IV group.
Ballooning degeneration of hepatocytes was consistently seen in group IV. All other organs appeared normal.
These results provide in vivo evidence that inadvertent intravenous injection of COVID-19 mRNA vaccine may induce myocardial pericarditis.
Briefly withdrawing the syringe plunger to eliminate blood aspiration is one possible way to reduce such risks, it is stated.
