At the start of the COVID-19 pandemic, the BNT162b2 (BioNTech-Pfizer) and mRNA-1273 (Moderna) mRNA vaccines were expediently designed and mass produced. Both vaccines produce the full-length SARS-CoV-2 spike protein for gain of immunity and have greatly reduced mortality and morbidity from SARS-CoV-2 infection. The distribution and duration of SARS-CoV-2 mRNA vaccine persistence in human tissues is unclear. Here, we developed specific RT-qPCR-based assays to detect each mRNA vaccine and screened lymph nodes, liver, spleen, and myocardium from recently vaccinated deceased patients. Vaccine was detected in the axillary lymph nodes in the majority of patients dying within 30 days of vaccination, but not in patients dying more than 30 days from vaccination. Vaccine was not detected in the mediastinal lymph nodes, spleen, or liver. Vaccine was detected in the myocardium in a subset of patients vaccinated within 30 days of death. Cardiac ventricles in which vaccine was detected had healing myocardial injury at the time of vaccination and had more myocardial macrophages than the cardiac ventricles in which vaccine was not detected. These results suggest that SARS-CoV-2 mRNA vaccines routinely persist up to 30 days from vaccination and can be detected in the heart.
Interesting, from my understanding, in assumedly healthy models, after 48 hours the majority of the mRNA in confined to the injection site, the lymphatic system, and the liver, with it leaving the liver soon after, so its odd seeing correlation of it lasting so long near the heart in those who died from SARS-CoV-2 within 30 days of receiving a vaccine.
I would like to see a follow up study including the hepatic and cardiac fitness of those who died in the same manner. Renal function was a strong factor in recovery, and there's pretty much no doubt about cardiac and hepatic function playing a role as well, but I wonder if these could be just as important and if the presence of vaccine mRNA outside of the injection site or lymph system could be used as reliable indicators for renal and cardiac health, as well as prognosis, in the future.