Since the beginning of the pandemic, doctors have observed that SARS Cov-2 targeted, in addition to the lungs, the heart, with a higher risk of developing serious cardiovascular disorders.
Since then, vaccines have arrived, and many of their detractors denounce a dangerous injection that poses a health risk. But what do the scientists say?
Researchers from the National University Hospital of Singapore reviewed international databases, covering more than 400 million doses of vaccines, to compare the risk of myopericarditis after an injection of a Covid vaccine and an injection of a flu or smallpox vaccine. , for example.
No explosion of heart inflammation cases
Myopericarditis is an inflammation of the heart tissue (myocardium) that extends to the pericardium (the membrane that surrounds the heart and the root of large blood vessels) that in some cases leaves severe and permanent heart damage.
This heart disorder is usually caused by viruses or bacteria. But in rare cases, it can also occur after vaccination.
Thus, the researchers did not find a notable and significant difference between the incidence of this heart disease after vaccination with the Covid-19 vaccine (18 cases per million doses) and the rest of the vaccines (56 cases per million doses). .
Quoted by medical newsDr. Kollengode Ramanathan, co-author of the study, says that “these results should strengthen public confidence in the safety of vaccines against Covid-19. »
In the case of the vaccination campaign against Covid-19, the vast majority of post-vaccinal myocarditis are mild and heal quickly: 95% of cases in adults are considered mild.
For children, 98.6% of cases are mild and do not require mechanical cardiac support.
A rare risk already taken into account by the health authorities
The study authors also noted that the risk of myopericarditis was higher in people who received messenger RNA vaccines (22.6 cases per million doses) than in those who received vaccines without mRNA (7.9 cases per million doses). These reported cases were more numerous in people under 30 years of age, but also in men and after the second dose of the Covid-19 vaccine.
In November 2021, the French health authorities had already taken into account the possible risks of myocarditis related to mRNA vaccines, by advising against the Moderna vaccine for people under 30 years of age.
This decision followed the publication of a French study which revealed an increased risk of myocarditis and pericarditis in young men under 30 years of age, especially after administration of a second dose of the Moderna vaccine.
However, the researchers point out that the risk of developing myocarditis after contracting Covid-19 is greater than the possibility of developing it after injecting a dose of the vaccine against the latter.