From the start of the pandemic, doctors observed that SARS Cov-2 targeted, in addition to the lungs, the heart, with an increased risk of developing serious cardiovascular disorders.
Since then, vaccines have arrived, and many of its detractors denounce a dangerous injection causing a health risk. But what do the scientists say?
Researchers from the National University Hospital in Singapore reviewed international databases, covering more than 400 million doses of vaccine, to compare the risk of myopericarditis after an injection of a Covid vaccine and an injection of a vaccine against flu or smallpox for example.
No explosion of cases of heart inflammation
Myopericarditis is an inflammation of the heart tissue (myocardium) extending to the pericardium (the membrane that envelops the heart and the root of the large blood vessels) which in some cases leaves serious and permanent heart damage.
This heart disorder is most often caused by viruses or bacteria. But in rare cases, it can also occur after vaccination.
Thus, the researchers found no notable and significant difference between the incidence of this cardiac pathology after vaccination with the vaccine against Covid-19 (18 cases per million doses) and the other 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-vaccination myocarditis is mild and heals quickly: 95% of cases in adults are considered mild.
For children, 98.6% of cases are mild and require no need for mechanical heart 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 non-mRNA vaccines (7.9 cases per million doses). These reported cases were more numerous in people under the age of 30, 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 linked 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 had revealed an increased risk of myocarditis and pericarditis in young men under 30, in particular after the administration of a second dose of Moderna vaccine.
However, the researchers point out that the risk of developing myocarditis after contracting Covid-19 is higher than the possibility of developing it after the injection of a dose of vaccine against the latter.