A new study published Tuesday in the peer-reviewed JAMA Cardiology journal reported a “higher than expected” number of myocarditis cases among male military members after the second dose of an mRNA vaccine against the CCP (Chinese Communist Party) virus.
The new study, a retrospective review of cases, noted that the observed number of cases of myocarditis—inflammation of the heart muscle—was still “relatively small.”
The case review involved patients in the U.S. military health system who experienced myocarditis after they received an mRNA vaccine dose for COVID-19—the disease caused by the CCP virus—between Jan. 1 and April 30.
It found that 23 males presented with “acute onset of marked chest pain” within four days of receiving a vaccine dose. Seven received the Pfizer-BioNTech vaccine and 16 received the Moderna vaccine, both of which use messenger RNA (mRNA) technology.
The group’s age ranged 20-51, with a median of 25. All “had a final diagnosis of myocarditis without infectious, ischemic, or autoimmune etiologies identified,” according to the study. Eight of the patients also underwent diagnostic scans that yielded results consistent with myocarditis. All have either recovered or were recovering at the time of the report’s publication.
Of the 23 males, 22 are military members and one is a retiree. All military members were “physically fit by military standards and lacking any known history of cardiac disease, significant cardiac risk factors, or exposure to cardiotoxic agents.”
Of the cohort, 20 people—19 of whom are military members—had their symptoms start after the second vaccine dose. Among the remaining three patients who had just one shot before reporting chest pain, all had “confirmed COVID-19 infection more than 2 months prior to vaccination.”
“The observed number of male military members who experienced myocarditis after their second dose of mRNA vaccine, while relatively small, is substantially higher than the expected number,” the study authors wrote, citing general population estimates that predicted eight or fewer cases of myocarditis from the 436,000 male military members who received two vaccine doses.
All 23 males “reflect substantial similarities in demographic characteristics, proximate vaccine dose, onset interval, and character of vaccine-associated myocarditis,” the study authors noted. “The consistent pattern of clinical presentation, rapid recovery, and absence of evidence of other causes support the diagnosis of hypersensitivity myocarditis.”
They later added, “Presentation after second vaccine dose or, in 3 patients, when vaccination followed SARS-CoV-2 infection, suggests that prior exposure was relevant in the hypersensitivity response.”
More than 2.8 million doses of mRNA COVID-19 vaccines were administered by the Military Health System between Jan. 1 and April 30. Of the total doses, 1,065,000 were second doses; 544,000 were second doses administered to military service members, and 436,000 were second doses administered to male military service members.
In an emailed statement to The Epoch Times on June 30, Pfizer said that it is aware of the “rare reports of myocarditis and pericarditis” after mRNA COVID-19 vaccination, which it acknowledges “predominantly in male adolescents and young adults.”
Citing the CDC, Pfizer said that it is “an extremely rare side effect, and only an exceedingly small number of people will experience it after vaccination. Patients have typically rapidly improved with conservative treatment.”
“It is important to note that CDC continues to strongly encourage COVID-19 vaccinations for eligible individuals aged 12 and older,” the company said. “With hundreds of millions of doses of the Pfizer-BioNTech COVID-19 vaccine administered globally, the benefit risk profile of our vaccine remains positive.”
Moderna has not responded to a request for comment to The Epoch Times as of late June 30.
Last week, the U.S. Food and Drug Administration (FDA) added a warning about the risk of developing heart inflammation—either myocarditis or pericarditis—to patient and provider fact sheets for the mRNA-based Moderna and Pfizer CCP virus vaccines. Pericarditis is inflammation of the outer lining of the heart.
The fact sheets warned of potential onset of myocarditis and pericarditis within a few days after receiving the vaccine, and “particularly following the second dose.”
Heart inflammation can also occur due to COVID-19.
Acting FDA Commissioner Janet Woodcock maintained that the benefits of receiving the shots outweigh the risk.
“The risk of myocarditis and pericarditis appears to be very low given the number of vaccine doses that have been administered,” she previously said in a statement. “The benefits of COVID-19 vaccination continue to outweigh the risks, given the risk of COVID-19 diseases and related, potentially severe, complications.”
The Centers for Disease Control and Prevention (CDC) said on June 23 that more than 1,200 cases of heart inflammation in adolescents and young adults who received the Pfizer or Moderna CCP virus vaccine have been reported. The majority of the patients were male, and the majority of cases were reported after the second dose of a vaccine.
Dr. Tom Shimabukuro, a CDC official, had presented the data to the CDC’s vaccine advisory committee. According to his presentation, heart inflammation occurred at a rate in 12- to 39-year-olds of “12.6 cases per million second doses of any mRNA vaccine in the 21 days following vaccination,” with rates higher in males.
The CDC in May started an investigation into a possible link between mRNA vaccines and myocarditis after Israel’s health ministry said in April it was monitoring a small number of cases of people developing heart inflammation after getting Pfizer’s vaccine. At the time, there were also reports that the Pentagon was tracking 14 cases of heart inflammation among people vaccinated through the military healthcare system.
On June 1, Israel’s health ministry said that the small number of myocarditis cases that were found in mainly young men who received the COVID-19 Pfizer vaccine were likely linked to the vaccination.
The FDA’s authorization of the Pfizer-BioNTech and Moderna vaccines for emergency use marked the first time it did so for vaccines that use mRNA technology.
According to the FDA, the mRNA vaccine contains a small piece of the CCP virus’s mRNA that instructs cells in the body to make the distinctive spike protein of the virus. When a person receives the vaccine, their body produces copies of the spike protein which “does not cause disease, but triggers the immune system to learn to react defensively, producing an immune response” against the CCP virus, according to the agency.
Dr. Tal Zaks, Moderna’s chief medical officer, previously said that while both Pfizer and Moderna vaccines use the same mRNA technology, the makeup of the vaccines aren’t identical, with some of the lipids or fats encasing the vaccines being different.
Update: A part of this article has been edited for clarity. A statement from Pfizer has been added.