Covid-19: with RNA vaccines, the risk of myocarditis and pericarditis is confirmed but infrequent – South West

Led by the Epi-Phare structure, which brings together Health Insurance (Cnam) and the Medicines Agency (ANSM), this case-control study focused on people aged 12 to 50 years hospitalized in France for myocarditis or pericarditis between May 15 and August 31, or 919 cases of myocarditis and 917 cases of pericarditis.

Myocarditis and pericarditis are inflammations of the heart. The first affects the myocardium, the main heart muscle, and the second the pericardium, the membrane that surrounds the heart.

Within 7 days after vaccination

As had been shown by pharmacovigilance reports, the results of the French study confirm that Pfizer and especially Moderna vaccines increase the risk of these diseases occurring within 7 days after vaccination.

Each case was compared to 10 “controls” of the same age, same sex and from the same department of residence. The risks of hospitalization for myocarditis or pericarditis were thus compared between vaccinated and unvaccinated in otherwise similar situations.

In men under 30

These risks appear to be more marked, even if low, in men under 30, especially after the second dose of Moderna. Vaccination would thus be the cause of 132 additional cases (37 cases in women) of myocarditis per million doses administered.

As for the risk of pericarditis, it also appears more marked after the Moderna vaccine in those under 30 years of age, in particular after the second dose which would be the cause of an excess of cases of about 18 per million doses in young men.

“When we weigh the effectiveness of vaccines against severe forms of Covid-19 (estimated at around 90%) and these existing but infrequent risks, and with favorable development, the benefit-risk ratio of vaccines does not is not called into question ”, assures Mahmoud Zureik, director of the Epi-Phare structure.

No deaths have been reported among those hospitalized.