Pfizer Finally Releases Myocarditis Study for Children Who Received COVID-19 Vaccine

Pfizer and its partner BioNTech have finally released the results of clinical trials exploring whether their COVID-19 vaccine causes subclinical heart inflammation. The companies found that multiple vaccine recipients suffered heart-related symptoms, but said none met the definition of myocarditis, or heart inflammation.

Researchers with the companies and other institutions analyzed the levels of troponin I, a sign of possible heart damage, in children aged 5 to 30 before and after receipt of the Pfizer-BioNTech vaccine. They also monitored participants for heart-related symptoms, including chest pain. If patients suffered symptoms, doctors examined them and researchers performed other tests, such as an electrocardiogram, as well as additional troponin measurements.

Ten vaccinated participants, including six under the age of 12, reported relevant symptoms. The researchers, though, said none had myocarditis after additional testing.

Among the younger children, half of the participants with the symptoms underwent troponin evaluations and four had electrocardiograms. All the results were normal, according to the researchers. One of the six had a cardiac MRI performed, and the MRI came back with abnormal results. But the results suggested viral infection, not cardiac abnormalities, they said.

Among the four people in the older group who experienced symptoms, one suffered chest discomfort and trouble breathing on the same day as receiving the shot. An electrocardiogram the next day revealed an ST elevation, and troponin levels in the individual were also significantly elevated.

But an echocardiogram and cardiac MRI both returned normal, and researchers said the case did not constitute myocarditis or a related condition called pericarditis.

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“I don’t know what to make of that,” Dr. Andrew Bostom, a heart expert who was not involved in the study, told The Epoch Times after reviewing the paper. “That could have been clinically defined as some sort of abnormality, some sort of cardiac abnormality.”

The other cases among the older group were also ruled not to be myocarditis, although the troponin data for three of the four was “not reported,” the researchers said.

That missing data is concerning, Dr. Bostom said.

Pfizer and BioNTech did not respond to requests for comment.

The researchers compared the percentage of participants who had elevated troponin to other groups. For 12- to 30-year-olds, the control group was composed of healthy people who had previously received two or three doses of the vaccine. That group received a placebo, while the study group received another shot.

For 5- to 11-year-olds, the control group was comprised of unvaccinated children who received placebos while the study group received one to three doses of the Pfizer-BioNTech vaccine.

Across both trials, exclusions included people with a history of severe adverse reactions to vaccines, and no participants had prior myocarditis.

A lower percentage of 12- to 30-year-olds who received a new vaccine dose had elevated troponin shortly after vaccination, when compared to the control group. The testing was done on the fourth day after receipt of a vaccine dose or placebo.

But one month after a dose or placebo, the percentage was higher among the newly vaccinated arm.

The rate of COVID-19 was also higher among the newly vaccinated people in the older group, with eight cases compared to two in the control arm.

In the younger children, the elevated troponins were higher among the vaccinated after each dose. No elevated troponin cases were detected in the unvaccinated cohort.

The new paper was submitted to the journal on Nov. 13, 2023, the journal said.

Dr. Bostom agreed.

“But that’s not exactly an earth shattering finding,” he said. “That’s the way you’re supposed to use troponin. We’re not supposed to go around and screen everyone for troponin elevation.”

Measuring troponin after symptoms like chest pain appear is useful, he added later.

Dr. Peter McCullough, a cardiologist who also reviewed the study, said that he found it lacking.

“Full comparisons of mean, median, range, stratified by cumulative doses received with parametric statistics would be needed in a thorough cardiac toxicology study,” Dr. McCullough told The Epoch Times in an email.

“Selection bias, loss to followup, and the majority of authors having a vested financial stake in the Pfizer/BioNTech COVID-19 vaccine are additional concerns. With the mass of studies demonstrating mRNA COVID-19 vaccination causes serious and fatal myocarditis, this study is not reassuring to the cardiovascular community,” he added.

Listed limitations in the new paper included being underpowered to detect myocarditis cases, while the lengthy conflicts of interest section included notes on many authors either being current or former Pfizer employees. The paper was also funded by Pfizer and BioNTech.