Data on Myocarditis Risk from COVID-19 Shots Hidden

• by Natasha Hobley

• Published December 16, 2025
• Risk & Failure Reports
•  

• The U.S. Food and Drug Administration’s (FDA) commissioner Marty Makary, MD, MPH recently said in a prepared statement that the Biden administration withheld data on heart inflammation risks from the mRNA COVID-19 vaccines. The statement was made less than a week after the FDA’s top vaccine regulator, Vinay Prasad, MD, MPH confirmed that at least 10 children died “after and because of receiving” the shots.¹

  “We have done more to study myocarditis and to go back and look at deaths of people, of children from the COVID vaccine,” Dr. Makary told NBC News in an interview. “Internal data submitted on myocarditis, we found that the Biden administration was sitting on data on myocarditis in young people, and it was not made public.”¹

  In response to the claims made by Makary, several former FDA officials issued a denunciation of the assertions published in The New England Journal of Medicine, stating that new proposals from the FDA are rejecting long-standing science.¹ Former FDA commissioner Robert Califf, MD wrote:

  As former commissioners of the FDA—who collectively guided the agency’s oversight for more than 35 years, through myriad public health crises—we are committed to medical product safety and identifying new medical evidence with the speed, rigor, and openness that the public should expect.” Califf continued: “We are deeply concerned by sweeping new FDA assertions about vaccine safety and proposals that would undermine a regulatory model designed to ensure that vaccines are safe, effective, and available when the public needs them most.²

  In March 2021, reports from both the United States and Israel emerged citing shortness of breath, chest pain, and a fluttering or pounding heart in some vaccine recipients. One month later, the U.S. Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunizations Practices (ACIP) met to discuss the side effects, and health officials concluded that there was a “likely association” between myocarditis and the vaccines.¹ The FDA eventually added the warning to the patient and provider fact sheets for Pfizer and Moderna.

  While the mainstream media continues to downplay risks, independent and whistleblower data has continuously shown a significant correlation between myocarditis and the COVID shots.

  Risk of mRNA COVID Shot Documented Since 2021

  Researchers who used data from December 2020 through August 2021 from the CDC’s Vaccine Adverse Event Reporting System (VAERS) found that the risk of myocarditis following the mRNA COVID-19 biologic is 133 times greater than the normal risk for myocarditis in the general population.³ In July of 2023 after all branches of the U.S. military mandated receipt of COVID shots, the military saw myocarditis cases spike by 130 percent when compared with a five-year average period from 2016 to 2020.⁴ In 2024, a preprint study involving over 1.7 million children found that myocarditis and pericarditis occurred only in vaccinated children.⁵

  A senior health official who worked under the Biden administration called Makary’s claim that data had been concealed “absurd” and said the comment would do “irrevocable harm” to public trust in the FDA.¹

  Makary said that the agency’s new findings about childhood deaths following vaccination stem from investigations after talking with families and reviewing autopsies. “These were kids who died immediately after getting the COVID shot,” he said. “They went into myocarditis, or other serious vaccine complications.”¹

  “When a healthy kid immediately gets a COVID shot and then develops a string of complications that results in a cascade resulting in the child’s demise,” Makary added. “That’s causal until proven otherwise.”¹ No official reports or studies have yet been released.

  FDA Required Pfizer and Moderna to Provide Additional Myocarditis Warnings

  In June 2025, the FDA finalized and announced new warnings for both the Pfizer and Moderna shot which will highlight cardiac risks. These warnings will provide additional information about myocarditis and pericarditis— both of which can potentially lead to long-term heart damage.⁶

  The labeling for the vaccines is now required to include information that specifically spells out the increased risks for young men. The following text is now required:

  Based on analyses of commercial health insurance claims data from inpatient and outpatient settings, the estimated unadjusted incidence of myocarditis and/or pericarditis during the period 1 through 7 days following administration of the 2023-2024 Formula of mRNA COVID-19 vaccines was approximately 8 cases per million doses in individuals six months through 64 years of age and approximately 27 cases per million doses in males 12 through 24 years of age.

  Follow-up information on cardiovascular outcomes in hospitalized patients who had been diagnosed with COVID-19 vaccine-associated myocarditis is available from a longitudinal retrospective observational study. Most of these patients had received a two-dose primary series of an mRNA COVID-19 vaccine prior to their diagnosis. In this study, at a median follow-up of approximately 5 months post-vaccination, persistence of abnormal cardiac magnetic resonance imaging (CMR) findings that are a marker for myocardial injury was common. The clinical and prognostic significance of these CMR findings is not known.⁶

   

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