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Myocarditis
Myocarditis is a condition of inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart. Myopericarditis is where both occur simultaneously. In all three cases, the body’s immune system causes inflammation in response to an infection or some other trigger.
Increased occurrence of myocarditis, pericarditis and myopericarditis has been associated with Covid-19 inoculations,1) along with Covid-19 infection.
COVID-19 Pandemic and Vaccines
| Incidence of Myocarditis Following the Second Dose of a Covid-19 mRNA Vaccine | ||||||
|---|---|---|---|---|---|---|
| Age 12 - 17 | Male Age 12-17 | Age 18 - 24 | Male Age 18-24 | Male Age < 40 | Rate from Sars-cov-2 | |
| Kaiser Permanente Study - Dec 27, 20212) | 1/1860 | 1/2650 | ||||
| Nature Medicine Paper - Dec 25, 20213) | - | - | 101 excess events per million (Moderna) | 30 excess events per million | ||
| USA FDA ACIP Meeting Presentation4) | 62.8 per million | 50.5 per million | ||||
Mechanisms of Action
Pausing Moderna’s COVID Vaccine for Younger Age Groups
On October 6, 2021 Sweden and Denmark said they will pause the use of Moderna’s COVID vaccine for younger age groups after reports of side effects, including myocarditis and pericarditis. Following suit was Finland October 7, Iceland October 8 and France November 8.
France's decision to pause was supported by a study from the French National authority for Health (HAS). 5) The HAS designed the study by taking cases of hospitalization of myo or pericarditis in inoculated people and matched them each to controls of similar age, sex & geography. They adjusted for history of myocarditis or pericarditis, history of SARS-CoV-2 infection etc. Essentially, they defined a signal (hospitalization for myo/peri within 7 days of inoculation of either Moderna or Pfizer) and compared it to a baseline (control of unvaxxed & uninfected).
What they found was for the second dose of Moderna for men under 30 (within 7 days of inoculation) an excess of hospitalization cases from myocarditis alone reaching ~131 per million doses. They also calculated an odds-adjusted ratio or OR (which is basically a multiple of the signal over baseline occurrence). 2-dose Moderna for men below 30 had an OR of ~80x (which is like saying 80x more risk vs. baseline) for myocarditis alone. For comparison SARS-CoV-2 infection in the previous month for myocarditis had a OR of ~7.9x.
Woman under 30 on the second dose of Moderna found an excess of 37 per million doses for myocarditis with an OR of ~40.6x. For Pfizer & myocarditis alone, men under 30 for the second doses found excess hospitalizations of 27 per million doses and an OR of ~10.9x, while woman saw an increase of 4 per million doses and an OR of ~11.4x.