Vaccine remains effective despite confirmed cases of myocarditis, new study shows – The HuffPost

Raneen Sawafta via Reuters

RISKS – Messenger RNA vaccines against Covid-19 increase the risk of myocarditis and pericarditis but this is infrequent and does not affect the benefit of the vaccination, highlighted a large French study published this Monday, November 8.

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.

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

Each case was compared to 10 “controls”, who have the same age, sex and department of residence, but did not have myocarditis. The risks of hospitalization for myocarditis or pericarditis were thus compared between vaccinated and unvaccinated in otherwise similar situations.

Higher risks 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 with the latter would thus be the cause of 132 additional cases of myocarditis per million doses administered.

In women under 30, the excess myocarditis attributable to the second dose of Moderna is estimated to be in the order of 37 per million doses.

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 around 18 per million doses in young men.

No deaths have been reported among people hospitalized for these conditions while following vaccination.

“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 AFP Mahmoud Zureik, director of the Epi-Phare structure.