As vaccination programs against Covid began around the world, it turned out that some people – especially young men – later developed myocarditis, a type of inflammation of the heart muscle or pericarditis, inflammation of the outer lining of the heart. While cases were rare, the findings were a cause for concern, with the risk of such heart disease being among the reasons cited by experts in the UK for delaying the expansion of the vaccination program in children. Research now shows that myocardial infarction – a general term that includes myocarditis and pericarditis – is not only uncommon after Covid vaccines, but the risk of developing them is no greater than that posed by other vaccines, such as vaccines against Covid. flu. “The overall risk of myocardial infarction does not appear to be different for this very new group of vaccines against Covid-19 than for traditional vaccines against other pathogens,” the authors write. Writing in The Lancet Respiratory Medicine, researchers in Singapore describe how they performed an analysis of 22 previously published studies covering more than 405 million doses of vaccine worldwide, which looked at the development of myopicarditis after vaccination. In total, 11 of the studies covered Covid vaccines, although many did not consider vaccinations under 12 years of age, while 11 considered vaccines for influenza, smallpox, polio and MMR (measles, mumps and rubella), among others. . The results reveal that the incidence of myopicarditis is low after a Covid vaccine, with an average incidence of approximately 18 cases per million doses. This is similar to the frequency after a flu vaccine and after other types of vaccination. When combined, Covid-free vaccines had an average incidence of approximately 56 cases of myopericarditis per million doses. The incidence is also much lower than the frequency after the smallpox vaccine – although the authors note that studies of the latter were conducted mainly among the US military, which consists mainly of young men, potentially influencing the results. Myocardial infarction after Covid vaccination was relatively more common in the case of mRNA vaccines, in younger people, after a second dose, and in men: the incidence was 10 times higher in men than in women under 30 years of age. However, even in young men, myocardial infarction rates after the Covid vaccine were comparable to other vaccines. The authors add that the risks of unusual side effects such as myopicarditis are offset by the benefits of the vaccine, noting that this includes a lower risk of infection, hospitalization, serious illness and death than Covid himself. However, they suggest that the study findings help to adapt the policy. For example, boys could be offered mRNA-free vaccines for Covid, although other issues may also influence such decisions, such as the availability of such vaccines. Dr Kollengode Ramanathan of the National University of Singapore, co-author of the study, said: the lesions. the Covid-19 vaccine, the local risk of exposure to Covid-19 infection at that time, and the risk of myopericarditis from Covid-19 infection itself at the time of vaccination of their adolescent children. Professor Beate Kampmann, director of the Vaccine Center at the London School of Hygiene & Tropical Medicine, who did not participate in the study, said it was important to consider the findings, but that the main message was myocardial infarction after the Covid vaccine was very rare. and not more common than after other vaccines. In addition, he said, the situation was resolved with anti-inflammatory treatment. “The risk of heart attack and severe damage from Covid-19 itself is significantly higher than this rare side effect, which mainly affects – and rarely – young men,” said Kampmann. Professor Sir Nilesh Samani, medical director at the British Heart Foundation, agreed. “Millions of people around the world have been vaccinated against Covid, almost all without complications,” he said. “Taking Covid-19 can lead to serious illness, including heart problems, and people who are vaccinated have a much lower risk of developing other serious complications caused by Covid-19.”
