FDA myocarditis warning

FDA Approves Required Updated Warning in Labeling of mRNA COVID-19 Vaccines Regarding Myocarditis and Pericarditis Following Vaccination

https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/fda-approves-required-updated-warning-labeling-mrna-covid-19-vaccines-regarding-myocarditis-and

mRNA COVID Shots Cause Myocarditis (FDA video)

Dr Vinay Prasad, Director of the Center for Biologics Evaluation and Research FDA.

https://www.youtube.com/watch?v=68QzzWGc4mI

June 25, 2025, FDA Safety Communication

6 months through 64 years

Approximately 8.4 cases per million doses

Initial and follow-up cardiac MRIs commonly showed signs of injury to the heart muscle

Males 12 through 24 years

Approximately 26.9 cases per million doses, 1/37,000

First reports of C-VAM

Feb 2021 (VAERS)

April, 2021, 2 deaths and 60 cases from Israel

(details sent to FDA and CDC in April 2021)

April 27th 2021, DCD statement denies myocarditis signal.

April 27th 2021, CDC was aware of 14 cases reported by US military

August 2021, FDA document (FOI) 1/5,000 (16 and 17 year old males)

Hong Kong, 1 / 2,700 hospitalised (13 to 18 males)

Vaccine safety link data, 1 / 2,000 (after 2nd dose in 18 to 24 males)

Vaccine safety link data, 64% of cases missed at first

First Pfizer booster, 1 / 6,800

Undoubtedly some deaths may be implicated

Deaths due to fulminant myocarditis

Undoubtedly people have subclinical myocarditis

Severe outcomes from covid declining, new risk benefit analysis coming soon.

Follow-up information on cardiovascular outcomes

From longitudinal retrospective observational study.

Most had received a two-dose primary series, prior to diagnosis.

Follow-up of approximately 5 months post-vaccination

Persistence of abnormal cardiac magnetic resonance imaging (CMR) findings,

that are a marker for myocardial injury in 60% of patients.

(Late gadolinium enhancement, LGE)

Australia data, (at 6 months) 67% LGE and 35% showing fibrosis

LGE literature review

92% are men

72% persistent

The clinical and prognostic significance of these CMR findings is not known.

LGE (from FDA slide)

Poor prognostic factor (multiple studies)

Associated with increased future cardiac events and mortality

25% admitted to ICU

This publication

To inform the public and healthcare providers

FDA has required and approved updates to the Prescribing Information for Comirnaty (mRNA) manufactured by Pfizer Inc. and Spikevax manufactured ModernaTX, Inc. to include new safety information about the risks of myocarditis and pericarditis following administration of mRNA COVID-19 vaccines.

Required to include information about:

(1) the estimated unadjusted incidence of myocarditis and/or pericarditis following administration of the 2023-2024 Formula of mRNA COVID-19 vaccines and

(2) the results of a study that collected information on cardiac magnetic resonance imaging (cardiac MRI) in people who developed myocarditis after receiving an mRNA COVID-19 vaccine.

Adverse Reactions section of the Prescribing Information and in the Information for Recipients and Caregivers.

Based on analyses of commercial health insurance claims data

Inpatient and outpatient settings

Estimated unadjusted incidence of myocarditis and/or pericarditis

(1 through 7 days of the 2023-2024 Formula)

In a post-approval U.S. study funded and co-authored by FDA

https://www.sciencedirect.com/science/article/pii/S2589537024003882?via%3Dihub

Follow-up on approximately 300 people who developed myocarditis

Some people in the study reported having heart symptoms approximately 3 months after developing myocarditis.

Improvement over time in some but not all people.

an mRNA COVID-19 vaccine. These studies are underway.

Suspected adverse events may be reported to the Vaccine Adverse Event Reporting System (VAERS), which is co-managed by the FDA and the CDC.

https://www.sciencedirect.com/science/article/pii/S2589537024003882?via%3Dihub

Other adverse reactions

Blood clotting disorders, thrombosis and thrombocytopenia

Postural orthostatic tachycardia syndrome (POTS)

Leg amputation (Alex)

Small nerve fibre neuropathy

Constant pain all over (Brianne)

Transverse myelitis and paralysis (Michael)

Persistent fatigue syndrome

Immune disorders

Guillain Barre syndromes

Bell’s palsy

Seizures

Allergies and anaphylaxis

New onset autoimmunity, lupus, rheumatoid arthritis, autoimmune hepatitis

Reproductive and menstrual irregularities

Infertility

Long post vaccine syndrome

Multisystem inflammatory syndrome in children

Death

Cancers