A Brief Overview

In late 2022, I published an article titled Autopsy Findings of Vaccinated People (With Covid Vaccines): An Update. I conducted a thorough review of the biomedical literature using the search terms “vaccine AND (covid OR sars-cov-2) AND (autopsy OR postmortem OR necropsy)", resulting in 123 articles identified by November 25, 2022. My analysis was split into two parts: Part I addressed 55 articles and Part II covered the remaining 68.

Part I focused on post-vaccination deaths due to thrombotic thrombocytopenia induced by DNA vaccines. The key finding was that deaths suspected to be vaccine-related were extremely rare, affecting less than 0.00005% of vaccinated individuals, with most cases attributed to pre-existing cardiovascular conditions.

Part II examined deaths following mRNA vaccination, which also predominantly stemmed from non-vaccine-related causes. A small fraction of fatalities were linked to fulminant myocarditis induced by mRNA vaccines, estimated at 1 in 20,000,000 (0.000005%) of vaccinated individuals.

These figures were derived from a combination of case reports, series, and cohort studies, divided by the total number of vaccinated individuals. However, a significant limitation of my initial calculations was that the cases were dispersed across various studies, leading to potential biases and underreporting. Additionally, I did not stratify fatality rates by age or use a consistent denominator.

A New Korean Study

The recently published study titled COVID-19 vaccination-related myocarditis: a Korean nationwide study, featured in the European Heart Journal on June 2, 2023, was conducted by Dr. Jae Yeong Cho and colleagues from notable Korean institutions.

Thanks to the Korea Disease Control and Prevention Agency (KDCA), which maintained records of all vaccinated individuals, the study utilized a mandatory reporting system for serious adverse events such as myocarditis post-vaccination. Healthcare professionals are legally required to report any such events, and individuals can also report them.

From February 26 to December 31, 2021, 44.2 million people aged over 12 received at least one dose of a COVID-19 vaccine, with Pfizer's mRNA being the most commonly administered. Among these, 1,533 suspected myocarditis cases were reported, but only 480 were confirmed as vaccine-related after thorough clinical and biopsy evaluations.

This results in an overall myocarditis incidence of 1.08 per 100,000 vaccinated individuals, with chest pain being the most frequent symptom and a median onset time of three days post-vaccination.

Subgroup analyses indicated that myocarditis was more prevalent in males than females (1.35 vs. 0.82 per 100,000) and highest among adolescent males aged 12-17 (5.29 per 100,000). The incidence was notably lower in females over 70 (0.16 per 100,000) and showed a slight increase after the second dose compared to the first (0.55 vs. 0.47 per 100,000), but was significantly reduced after the third dose (0.24 per 100,000). Recipients of Moderna's mRNA vaccine had the highest incidence (2.3 per 100,000).

Among the 480 confirmed cases, 95 (19.8%) were severe, requiring intensive care, ECMO, or heart transplantation, with 21 fatalities. Autopsies were performed on sudden deaths post-vaccination, revealing that only 8 cases were attributable to vaccine-related myocarditis, all occurring within a week of mRNA vaccination in individuals under 45 years.

Understanding the Data: Suspected vs. Confirmed Events

An important takeaway from the Korean study is that only 31% of suspected myocarditis cases were clinically confirmed, indicating that the majority of suspected adverse events were unrelated to the vaccine. This finding resonates with a previous German study, which found similar results.

The German study analyzed 18 autopsy cases of suspected vaccine-related deaths, with only 2 confirmed as vaccine-related, attributing the rest to pre-existing health conditions.

Both studies emphasize that suspected vaccine-related deaths often result from causes unrelated to vaccination.

Incidence Insights

From the Korean study, 21 clinically confirmed vaccine-related myocarditis cases resulted in fatalities, translating to 0.000047% of the 44.2 million vaccinated individuals (1 in 2.1 million). However, just 8 were autopsy-confirmed, accounting for 0.000018% (1 in 5.5 million).

Focusing on individuals under 45 years—where all fatal cases occurred—about 19.7 million vaccinated individuals fall within this age group. With 71% receiving mRNA vaccines, an estimate of 14 million individuals under 45 received these vaccines, resulting in a fatal myocarditis incidence of 0.000057% (1 in 1.75 million).

Overall, this suggests that the incidence of fatal myocarditis linked to COVID-19 vaccines is likely between 1 in 2 to 5 million vaccinated individuals, particularly higher in younger males receiving mRNA vaccines.

Concluding Remarks

The Korean study addresses the shortcomings of my prior work by systematically collecting data and stratifying it by age and vaccine type. Nevertheless, it reaffirms the key points from my earlier analysis: most suspected vaccine-related adverse events are not causally linked to vaccination, and while fatal myocarditis can occur, it remains extremely rare.

It is crucial to interpret these findings in context, as some may misrepresent the data to suggest that the 8 confirmed cases of sudden cardiac death are definitively vaccine-related without considering the overall vaccinated population.

If you’ve read this far, thank you! You can subscribe to my Medium email list for updates. If you want to support my work, consider becoming a member or leaving a tip. For more insights, check out my previous articles on autopsy findings related to COVID-19 vaccinations.