Myocarditis is a potentially lethal complication following mRNA-based COVID-19 vaccines, according to German scientists who studied the autopsy findings of individuals who died unexpectedly days after receiving a COVID-19 vaccine.
In a study published on Nov. 27 in Clinical Research of Cardiology, scientists examined data from the federal state registry on autopsies of 35 persons who received a COVID vaccine up to 20 days before their death.
Among the 35 cases, autopsies revealed other causes of death due to pre-existing illnesses in 10 individuals—which were excluded from further analysis. Cardiac autopsy findings consistent with myocarditis were found in five of the remaining 25 cases found unexpectedly dead at home within 20 days following COVID vaccination.
All five people (three men and two women) had received Pfizer or Moderna’s COVID-19 vaccine within seven days of their death, with a mean of 2.5 days. The median age of death was 58 years (range 46–75 years).
Four individuals died after receiving their first COVID vaccine dose and one died after receiving the second dose. None of the individuals had COVID-19 before being vaccinated or at the time of death.
Autopsy findings, a lack of evidence of other causes of death and the timing of vaccination shortly before the deaths allowed researchers to conclude that vaccination was the “likely cause” of myocarditis and that the cardiac condition was “the cause of sudden death” in three cases.
Of the three cases, one person was found dead 12 hours after vaccination, another complained of nausea and was found dead soon thereafter and the remaining individual was found dead at home.
In one case, myocarditis was believed to be the cause of death, but researchers also detected a herpes virus. In another case, researchers did not have any explanation for the death outside of vaccination but noticed the inflammation was “discrete and mainly observed in the pericardial fat.” Therefore, these two deaths were classified as “possibly caused by vaccination.”
Myocarditis is heart muscle inflammation that can lead to cardiac arrhythmia and death. According to the National Organization for Rare Disorders, myocarditis can result from infections but is more commonly the result of the body’s immune reaction to initial heart damage.
Pericarditis is inflammation of the tissue surrounding the heart that can cause sharp chest pain and other symptoms.
“In general, a causal link between myocarditis and anti-SARS-CoV-2 vaccination is supported by several considerations,” including the “close temporal relation to vaccination,” the “absence of any other significant pre-existing heart disease,” and the negative testing for any “myocarditis-causing infectious agents,” the researchers said.
“Interestingly, we recorded infammatory foci predominantly in the right heart, which may suggest a gradual blood-stream derived dilution effect and based on this finding it is at least tempting to speculate that inadvertent intravascular vaccine injection may be contributing,” they added.
One limitation of the study included the small cohort size.
The U.S. Centers for Disease Control and Prevention recommends COVID-19 vaccination for nearly all people aged 6 months and older, and continues to claim the benefits of the vaccines outweigh the risks.